When Bloom changes his mind about having lunch in Burton's restaurant, he performs a little charade: "Mr Bloom raised two fingers doubtfully to his lips. His eyes said: / — Not here. Don't see him. / Out. I hate dirty eaters. / He backed towards the door." The gesture of putting two fingers to one's lips seems perhaps universally to indicate the condition of being absorbed in thought. Bloom uses it to sell a small social fiction covering his actual reasons for leaving the restaurant.
Rather than allowing revulsion to appear in his face, Bloom adopts the posture of someone scanning the room for an acquaintance, not finding him, and determining to seek him elsewhere. Joyce creates this dumbshow not only by having Bloom place two fingers on his lips but also via the remarkable narrative strategy of giving his eyes a speaking part. Together, the two gestures create a white lie whose purpose may be to spare the feelings of others. Bloom is a courteous man, so one might suppose that he wishes to let the people in the restaurant know that something other than disgust motivates his departure.
But in the crowded, noisy, and sloppy environs of the Burton it is hard to imagine either the harassed waiters or the monstrously scarfing diners caring very much about the sudden departure of a newly arrived customer. They are what Peter Kuch, writing about another of Bloom's charades, calls "a wholly imagined audience." Bloom seems to be in the habit of masking his thoughts even in social situations where he is not particularly vulnerable or offensive—suggesting that this is an unusually self-conscious person, keenly attuned to the potential hostility of other human beings and very susceptible to shame. This interpretation is consistent with the hallucinations of Circe, in which Bloom is regularly accused of doing shameful things and regularly justifies or lies about his intentions.