The way the last page of this chapter calls back to the last page of last chapter (but with "WHO AM I?" instead of "WHO IS THAT?", and with a different person making the same Scary Face) strikes me as more funny than anything, not that the "Who am I?" question isn't interesting. Not having enough of an understanding of her brother to imitate him, i'd think she has to either come up with some brotherly likes/interests to pretend to like because she assumes they're appropriate or to express her own actual wants.
of course, her whole plan involves suppressing her own actual wants as penance
but of course, narratively, you'd expect her to get more in touch with her own wants over the course of the story