The twentieth trump shows the general resurrection: an angel sounding a trumpet, and figures rising from tombs. It is the most explicitly Christian image in the deck and the least ambiguous, because it illustrates a specific and universally known doctrine rather than an allegory anyone had to work out.
Its interest lies in its position. In several fifteenth-century Italian orderings this card is not the twentieth but the last, ranking above the World, which is entirely logical if the sequence is understood as ending with the end of the world. In other orderings the World is last. The regional variation in trump order is well attested and is one of the strongest arguments against any theory that the sequence encodes a fixed doctrine: the cities that played the game did not agree on what came at the top of it.
The occultists inherited the French order, in which the World is twenty-one, and built their systems on it. The Golden Dawn assigned Judgement the letter Shin, the element Fire, and the thirty-first path from Hod to Malkuth. Shin is one of the three Mother letters and its element is fire, which suits a card of trumpets and awakening; Eliphas Levi, working from a different arrangement, had given Shin to the Fool.
Crowley renamed the card The Aeon and rebuilt it entirely around the Thelemic doctrine of a new age, dropping the resurrection scene. That is the single largest departure from traditional imagery in his deck, and it is a departure of content rather than style.