Solina's good at editing herself into whatever form she wants. It's a bit hard to explain, but she has some weird videogame like control over herself and her possessions.

I don't know how or when she got access to that but... apparently that's how she works. Apparently whenever she's absent she like... literally stops existing here and exists in her own little home. like a pocket dimension I assume. She doesn't want people knowing how she works.

She does want people trying to figure out how her insides work though, and that invitation is always open, like her mouth along with it.