Have any prominent theologians written on what the ascension looked like?

Douglas Farrow, a Catholic theologian, published in 1999 a book dedicated to the Ascension, called Ascension and Ecclesia. There, he argues that (probably not a novel idea) the ascension of Jesus is the same even described in Daniel 7:13-14. As he says:

What Daniel envisioned from above, therefore, Luke is now able to chronicle from below (p.25)

Daniel's verses are:

I saw one like a human being coming with the clouds of heaven. And he came to the Ancient One and was presented before him. To him was given dominion and glory and kingship, that all peoples, nations, and languages should serve him. His dominion is an everlasting dominion that shall not pass away, and his kingship is one that shall never be destroyed.

Thus, if correct, at least from the "Heaven's perspective", Daniel gives you an account of the ascension.

Alexander MacLaren discussed the mode of the ascension at length in at least three different places:

• his exposition of 2 Kings 2:11, which contrasts the translation of Elijah and the ascension of Christ

  There is no outward sign to accompany His slow upward movement through the quiet air. No blaze of fiery chariots, nor agitation of tempest is needed to bear Him heavenwards. The outstretched hands drop the dew of His benediction on the little company, and so He floats upward, His own will and indwelling power the royal chariot which bears Him, and calmly ‘leaves the world and goes unto the Father.’ The slow, continuous movement of ascent is emphatically made prominent in the brief narratives, both by the phrase in Luke, ‘He was carried up,’ which expresses continuous leisurely motion, and by the picture in the Acts, of the disciples gazing into heaven ‘as He went up,’ in which latter word is brought out, not only the slowness of the movement, but its origin in His own will and its execution by His own power.

  Nor is this absence of any vehicle or external agency destroyed by the fact that ‘a cloud’ received Him out of their sight, for its purpose was not to raise Him heavenward, but to hide Him from the gazers’ eyes, that He might not seem to them to dwindle into distance, but that their last look and memory might be of His clearly discerned and loving face. Possibly, too, it may be intended to remind us of the cloud which guided Israel, the glory which dwelt between the cherubim, the cloud which overshadowed the Mount of Transfiguration, and to set forth a symbol of the Divine Presence welcoming to itself, His battle fought, the Son of His love.

• his exposition of Luke 24:50-51

  He ascends on high at last, and yet with no pomp nor visible splendour to the world, but only in the presence of a handful of loving hearts, choosing some dimple of the hill where its folds hid them from the city. As He came quietly and silently into the world, so quietly and silently He passed thence. In this connection there is more than the picturesque contrast between the rapture of Elijah, with its whirlwind, and chariot of fire and horses of fire, and the calm, slow rising, by no external medium raised, of the Christ. It was fit that the mortal should be swept up into the unfamiliar heaven by the pomp of angels and the chariot of fire. It was fit that when Jesus ascended to His ‘own calm home, His habitation from eternity,’ there should be nothing visible but His own slowly rising form, with the hands uplifted, to shed benediction on the heads of the gazers beneath.

• his exposition of Acts 1:4-14

  The calm simplicity of the account of the Ascension is remarkable. So great an event told in such few, unimpassioned words! Luke’s Gospel gives the further detail that it was in the act of blessing with uplifted hands that our Lord was parted from the Eleven. Two expressions are here used to describe the Ascension, one of which (‘was taken up’) implies that He was passive, the other of which (‘He went’) implies that He was active. Both are true. As in the accounts of the Resurrection He is sometimes said to have been raised, and sometimes to have risen, so here. The Father took the Son back to the glory, the Son left the world and went to the Father. No chariot of fire, no whirlwind, was needed to lift Him to the throne. Elijah was carried by such agency into a sphere new to him; Jesus ascended up where He was before.

  No other mode of departure from earth would have corresponded to His voluntary, supernatural birth. He carried manhood up to the throne of God. The cloud which received Him while yet He was well within sight of the gazers was probably that same bright cloud, the symbol of the Divine Presence, which of old dwelt between the cherubim. His entrance into it visibly symbolised the permanent participation, then begun, of His glorified manhood in the divine glory.

  ... He who comes will be the very Jesus who went; that His coming will be, like His departure, visible, corporeal, local.

Have any prominent theologians written on what the ascension looked like?

Dr John Gill, Particular Baptist, commented that although it is not noted in either testament, Jesus' ascension must have been accompanied by "a shout, with the voice of the archangel & with the Trump of God" (1 Thess. 1:16) because He is said to return "in like manner" (Acts 1:11). Compare Psalm 47:5, Dr Gill's Commentary on Acts: "He having done his work on earth he came about, went up from earth to heaven in human nature, really, locally, and visibly, in the sight of his apostles, attended by angels, and with their shouts and acclamations, which are here meant; the Lord with the sound of the trumpet; which circumstance, though not related in the account of Christ's ascension in the New Testament, yet inasmuch as the angels say he shall descend in like manner as he ascended, and that it is certain he will descend with a shout, with the voice of the archangel, and the trump of God; so that if his ascent was as his descent will be, it must be then with a shout, and the sound of a trumpet, (Acts 1:10)."

Similarly, Augustine of Hippo stated that, "He must return on a cloud as that is how He departed. To quote Augustine, "...And because there the angels even said, emphasized text He will come in the same way as you saw Him going into heaven, One should bellieve with good reason that He is not only going to come in the same body but also in a cloud, since He will come as He left, and a cloud supported Him when He went away." (Early Christian Voices in Texts, Traditions & Symbols, John Hermann & Annewies Van Den Hoek, pp.315, 316)

What we are informed about as to the appearance of the Ascension is that it occurred in a deliberately secluded location, Bethany (Luke 24: 50) having walked over the summit of the Mount of Olives a further 1 1/2 miles and 600 feet lower to Bethany, which was completely out of sight of Jerusalem. Further he was accompanied only by His closest 11 disciples (Judas being dead & Matthias not yet chosen) & only whilst He was disappearing was their wonderment & reverie interrupted by the "two men in white" (Acts 1:10,11) whom some commentators believe to be Heaven's witnesses, Moses & Elijah (cf. Rev.11:3; Zech.4:14; Matt.17:3;Luke 24:4)

Hence we may glean something of what the Ascension looked like, notwithstanding the comments of Gill & Augustine. As with Christ's Post-Resurrection/Pre-Ascension ministry it was a very private affair without fanfare & restricted solely to believers. And we are informed that Jesus will return or "shall so come in like manner" (Acts 1:11).