In Nausicaa Bloom thinks of "Mutoscope pictures in Capel street: for men only. Peeping Tom." Mutoscopes were coin-operated boxes that allowed customers to advance a reel of film by turning a handle. Like photographs before them, these early motion pictures were quickly turned to prurient uses, making money by enticing passers-by to watch a moving peep-show. In Circe, a mutoscope motion picture from the early 1900s called What the Butler Saw provides the basis for a fantasy in which Bloom becomes a valet invited to "apply your eye to the keyhole and play with yourself while I just go through her a few times."
Mutoscopes were sometimes called "What the Butler Saw machines," because the short film of that name commented meta-cinematically on the action of staring at half-naked women through a slot. It showed a woman undressing in her bedroom, seen as if the viewer were looking through a keyhole.
Bloom seems acutely aware of the voyeuristic possibilities that cameras and film-viewing devices were opening up in his time. In Circe, in addition to asking "May I bring two men chums to witness the deed and take a snapshot?," he thinks in photographic or cinematographic terms while he contemplates the deed: "(His eyes wildly dilated, clasps himself.) Show! Hide! Show! Plough her! More! Shoot!" The "shoot" of Boylan's orgasm becomes indistinguishable from a film shoot, and the showing and hiding of Boylan's penis and Molly's vagina becomes the occasion for thinking about what is hidden and what is shown in peep shows.
In an essay titled "Joyce, Early Cinema and the Erotics of Everyday Life," published in Roll Away the Reel World: James Joyce and Cinema, ed. John McCourt (Cork University Press, 2010), Katherine Mullin argues that Bloom "longs for the camera's power to capture the spectacle he craves" (48)—voyeuristic spectacles of beautiful women laid bare to the eye. This scene in Circe, Mullin concludes, "savagely fulfills Bloom's cinematic ambitions" (55).
What the Butler Saw offered no more than female nakedness, but the title implied something more. The phrase had been current in British popular culture since the 1886 divorce trial of Lord Colin Campbell and his lady, the Irish-born Gertrude Elizabeth Blood, who was accused of having committed adultery with four different men. (For her part, Lady Campbell had won a legal separation from her husband in 1884, on the grounds that he had knowingy infected her with a venereal disease acquired before their marriage in 1881. Both parties filed for divorce after the separation.) In the very well publicized divorce trial, the Campbells' butler testified that he had witnessed his lord's wife copulating with Captain Eyre Massey Shaw of the Metropolitan Fire Brigade, viewing the busy couple through a keyhole. The members of the jury were escorted to the Campbells' London home to verify the plausibility of the butler's testimony.
It is reasonable to suppose that Bloom, like almost everyone else in London and Dublin, is aware of the notorious divorce trial and the scandalous testimony on which it turned. When he applies his eye to a keyhole in Circe, what he sees is not a woman undressing, but an undressed woman being violated by a man other than her husband.