I think/hope OP was talking about the additional info section.
The common app essay can be about anything - her love of whatever, a shell she found on the beach, how she loves a nice restaurant, a tree she sees out her window, the yellow fuzz on tennis racket strings.
It doesn’t have to be specifically - a here’s who I am, although hopefully that comes through in whatever she writes about - but it doesn’t need to be a straight this is me.