Uhh wow, asking about gem theory, huh. Steven doesn't actually know a heck of a lot about that, because whenever Pearl tries to explain it to him he mostly gets distracted by the practical effects of things.

"Uh..." What does she mean, anyway? They have gems because...they do? "I think we need our gems to exist. The physical forms the other gems have are just like...projections! Or holograms!" He lifts up his hands, gesturing in a way that is not actually helpful to his point.