This quoted from Raja Yoga book of Swamu Vivekananda. This may be a way of seeing how the devas look.

Another thing that may happen is divya dristi. I have read about drivya drishti in Bhagavad Gita. In BG, Sri Krishna gives drivya drishti to Arjuna and then Arjuna is able to see God in his Vishwaroop.

Another theory is that Gods themselves revealed themselves to Certain sages and rishis. This also happened in Mahabharat.

Kesava, that slayer of hostile heroes burst out into a loud laughter. And as the high-souled Sauri laughed, from his body, that resembled a blazing fire, issued myriads of gods, each of lightning effulgence, and not bigger than the thumb. And on his forehead appeared Brahman, and on his breast Rudra. And on his arms appeared the regents of the world, and from his mouth issued Agni, the Adityas, theSadhyas, the Vasus, the Aswins, the Marutas, with Indra, and the Viswedevas. And myriads of Yakshas, and the Gandharvas, and Rakshasas also, of the same measure and form, issued thence. And from his two arms issued Sankarshana and Dhananjaya. And Arjuna stood on his right, bow in hand, and Rama stood on his left, armed with the plough. And behind him stood Bhima, and Yudhishthira, and the two sons of Madri, and before him were all the Andhakas and the Vrishnis with Pradyumna and other chiefs bearing mighty weapons upraised. And on his diverse arms were seen the conch, the discus, the mace, the bow called Saranga, the plough, the javelin, the Nandaka, and every other weapon, all shining with effulgence, and upraised for striking. And from his eyes and nose and ears and every part of his body, issued fierce sparks of fire mixed with smoke. And from the pores of his body issued sparks of fire like unto the rays of the sun. And beholding that awful form of the high-souled Kesava, all the kings closed their eyes with affrighted hearts, except Drona, and Bhishma, and Vidura, endued with great intelligence, greatly blessed Sanjaya, and the Rishis, possessed of wealth of asceticism,for the divine Janardana gave unto them this divine sight on the occasion. And beholding in the (Kuru) court that highly wonderful sight, celestial drums beat (in the sky) and a floral shower fell (upon him). And the whole Earth trembled (at the time) and the oceans were agitated. And, O bull of the Bharata's race, all the denizens of the earth were filled with great wonder. Then that tiger among men, that chastiser of foes, withdrew that divine and highly wonderful, and extremely varied and auspicious form. And arm-in-arm with Satyaki on one side and Hridika's son (Kritavarman) on the other, and obtaining permission of the Rishis, the slayer of Madhu went out.

Another theory is that they went into Samadhi (or Turriya I am not sure which) in which they heard the divine truths.

This quoted from Raja Yoga book of Swami Vivekananda. This may be a way of seeing how the devas look.

Another thing that may happen is divya dristi. I have read about drivya drishti in Bhagavad Gita. In BG, Sri Krishna gives drivya drishti to Arjuna and then Arjuna is able to see God in his Vishwaroopa.

Another theory is that Gods themselves revealed themselves to Certain sages and rishis. This also happened in Mahabharata.

Kesava, that slayer of hostile heroes burst out into a loud laughter. And as the high-souled Sauri laughed, from his body, that resembled a blazing fire, issued myriads of gods, each of lightning effulgence, and not bigger than the thumb. And on his forehead appeared Brahman, and on his breast Rudra. And on his arms appeared the regents of the world, and from his mouth issued Agni, the Adityas, theSadhyas, the Vasus, the Aswins, the Marutas, with Indra, and the Viswedevas. And myriads of Yakshas, and the Gandharvas, and Rakshasas also, of the same measure and form, issued thence. And from his two arms issued Sankarshana and Dhananjaya. And Arjuna stood on his right, bow in hand, and Rama stood on his left, armed with the plough. And behind him stood Bhima, and Yudhishthira, and the two sons of Madri, and before him were all the Andhakas and the Vrishnis with Pradyumna and other chiefs bearing mighty weapons upraised. And on his diverse arms were seen the conch, the discus, the mace, the bow called Saranga, the plough, the javelin, the Nandaka, and every other weapon, all shining with effulgence, and upraised for striking. And from his eyes and nose and ears and every part of his body, issued fierce sparks of fire mixed with smoke. And from the pores of his body issued sparks of fire like unto the rays of the sun. And beholding that awful form of the high-souled Kesava, all the kings closed their eyes with affrighted hearts, except Drona, Bhishma, and Vidura, endued with great intelligence, greatly blessed Sanjaya and the Rishis possessed of wealth of asceticism, for the divine Janardana gave unto them this divine sight on the occasion. And beholding in the (Kuru) court that highly wonderful sight, celestial drums beat (in the sky) and a floral shower fell (upon him). And the whole Earth trembled (at the time) and the oceans were agitated. And, O bull of the Bharata's race, all the denizens of the earth were filled with great wonder. Then that tiger among men, that chastiser of foes, withdrew that divine and highly wonderful, and extremely varied and auspicious form. And arm-in-arm with Satyaki on one side and Hridika's son (Kritavarma) on the other, and obtaining permission of the Rishis, the slayer of Madhu went out.

Another theory is that they went into Samadhi (or Turiya I am not sure which) in which they heard the divine truths.

Chapter 13 of Shiva Gita-

Shivji says-

Brahman is mere existence, consciousness, infinitude and bliss; it is devoid of any attribute and inaccessible to mind and speech -9-

I (Brahman) am existence, supreme bliss, self luminosity and the nature of consciousness. (When the world of nescience is destroyed by true knowledge)there is no time, nor the five elements, no quarters nor intermediary directions. -14-

(When ignorance is destroyed) there is nothing that remains other than myself. That I am alone. -15-

Here we see that Lord Shiva is without attribute, meaning he has no form, but in chapter 7-

Sri Suta says-

Having said this the Lord blesses him (Rama) with divine vision. Then he (Rama) saw the form (of the Lord) resembling the subterranean fire. -12-

Seeing that form, luminous like millions lightning flashes and, striking intense terror even among the brave, Rama, in sheer fright, collapsed on his knees to the ground.

These verses indicate that God does have a form, and many forms as earlier Shivji was in the form with a blue throat and a snake around his neck, but he gives divine vision to Rama so he can see his vishwaroopa (Which God also shows to Arjun in Bhagavad Gita).

We see this is in Bhagavad Gita too-

Sri Krishna says-

Those who fix their minds on My personal form and are always engaged in worshiping Me with great and transcendental faith are considered by Me to be most perfect. (BG 12.2)

For those whose minds are attached to the unmanifested, impersonal feature of the Supreme, advancement is very troublesome. To make progress in that discipline is always difficult for those who are embodied. (BG 12.3)

Hence, we infer God is formless, devoid of all qualities but, at the same time he also has many forms and all the divine qualities.

“Think of the universe as an ocean of ether, consisting of layer after layer of varying degrees of vibration under the action of Prana; away from the centre the vibrations are less, nearer to it they become quicker and quicker; one order of vibration makes one plane. Then suppose these ranges of vibrations are cut into planes, so many millions of miles one set of vibration, and then so many millions of miles another still higher set of vibration, and so on. It is, therefore, probable, that those who live on the plane of a certain state of vibration will have the power of recognising one another, but will not recognise those above them. Yet, just as by the telescope and the microscope we can increase the scope of our vision, similarly we can by Yoga bring ourselves to the state of vibration of another plane, and thus enable ourselves to see what is going on there. Suppose this room is full of beings whom we do not see. They represent Prana in a certain state of vibration while we represent another. Suppose they represent a quick one, and we the opposite. Prana is the material of which they are composed, as well as we. All are parts of the same ocean of Prana, they differ only in their rate of vibration. If I can bring myself to the quick vibration, this plane will immediately change for me: I shall not see you any more; you vanish and they appear. Some of you, perhaps, know this to be true.”

This quoted from Raja Yoga book of Swamu Vivekananda. This may be a way of seeing how the devas look.

Another thing that may happen is divya dristi. I have read about drivya drishti in Bhagavad Gita. In BG, Sri Krishna gives drivya drishti to Arjuna and then Arjuna is able to see God in his Vishwaroop.

Another theory is that Gods themselves revealed themselves to Certain sages and rishis. This also happened in Mahabharat.

SECTION CXXXI of the Udyoga Parva

Kesava, that slayer of hostile heroes burst out into a loud laughter. And as the high-souled Sauri laughed, from his body, that resembled a blazing fire, issued myriads of gods, each of lightning effulgence, and not bigger than the thumb. And on his forehead appeared Brahman, and on his breast Rudra. And on his arms appeared the regents of the world, and from his mouth issued Agni, the Adityas, theSadhyas, the Vasus, the Aswins, the Marutas, with Indra, and the Viswedevas. And myriads of Yakshas, and the Gandharvas, and Rakshasas also, of the same measure and form, issued thence. And from his two arms issued Sankarshana and Dhananjaya. And Arjuna stood on his right, bow in hand, and Rama stood on his left, armed with the plough. And behind him stood Bhima, and Yudhishthira, and the two sons of Madri, and before him were all the Andhakas and the Vrishnis with Pradyumna and other chiefs bearing mighty weapons upraised. And on his diverse arms were seen the conch, the discus, the mace, the bow called Saranga, the plough, the javelin, the Nandaka, and every other weapon, all shining with effulgence, and upraised for striking. And from his eyes and nose and ears and every part of his body, issued fierce sparks of fire mixed with smoke. And from the pores of his body issued sparks of fire like unto the rays of the sun. And beholding that awful form of the high-souled Kesava, all the kings closed their eyes with affrighted hearts, except Drona, and Bhishma, and Vidura, endued with great intelligence, greatly blessed Sanjaya, and the Rishis, possessed of wealth of asceticism,for the divine Janardana gave unto them this divine sight on the occasion. And beholding in the (Kuru) court that highly wonderful sight, celestial drums beat (in the sky) and a floral shower fell (upon him). And the whole Earth trembled (at the time) and the oceans were agitated. And, O bull of the Bharata's race, all the denizens of the earth were filled with great wonder. Then that tiger among men, that chastiser of foes, withdrew that divine and highly wonderful, and extremely varied and auspicious form. And arm-in-arm with Satyaki on one side and Hridika's son (Kritavarman) on the other, and obtaining permission of the Rishis, the slayer of Madhu went out.

Another theory is that they went into Samadhi (or Turriya I am not sure which) in which they heard the divine truths.