Senhor Raimundo Silveira is Macabéa's boss, and he's not a very nice one. The first time we meet Mr. Silveira, he's telling Macabéa that he's going to fire her soon because he's tired of her typing mistakes. The narrator tells us that Mr. Silveira tells her this news pretty bluntly, but that this bluntness is prompted by Macabea's "foolish expression," a facial expression "as if begging to be slapped" (3.29). When he coldly tells her this news, she has nothing to say in return, but she feels like she should say something to show him respect.
For all that he's cold and blunt, Macabéa is secretly infatuated with Mr. Silveira. Probably because he's one of the only people who's ever shown her any sympathy, even if that's not very much. The extent of his kindness? He decides not to fire her right away.