While there’s certainly a lot to discuss regarding sexuality and gender in terms of the scene in which Bello/a dominates a feminized Bloom, I’d like to focus on the use of animal imagery in that scene.
Most consistent is Bloom’s transformation into some kind of hog within this sequence. Bloom “sinks on all fours, grunting, snuffling, rooting at [Bello’s] feet”(15.2851-2852) after a shout of “Truffles!” in reference to the act of a hog rooting for truffles in the earth. Throughout the scene, Bloom squeals, bleats, and crawls under a table. Aside from the most obvious meaning of this animality as the ultimate form of subhuman subjugation, there also seems to be a reference here to the pig’s feet that Bloom carries in his pocket earlier in the episode, and even to the pork kidney that he eats in Episode 4. The reference is at the same time a nod to Bloom’s perceived lapse in Judaism – in not keeping Kosher – and to the “piggishness” of his unrestrained gustatory and, especially, sexual appetites.
Bello, however, is also given animal characteristics within this fantasy. Even before Bloom’s newfound piggishness is introduced, Bello’s foot is transformed into a “plump buskined hoof”(15.2810) which speaks to Bloom directly, and later he develops “purple gills”(15.2857). These references seem harder to pin down, given their vagueness of species, although they might be expressions more of a fleshly monstrosity than any particular animal. Despite this, however, it is only parts of Bello’s body that become inhuman in this way, as opposed to Bloom, who seems wholly transformed in shape and behavior.