It looks like a set of themes installed that I neither asked for, can't remove, and if I do use might vanish at any time leaving me with a forced visual change.

It looks like a set of themes installed that I neither asked for, can't remove, and if I do use might vanish at any time leaving me with a forced visual change. I'm not sure what the value is here - it's just a temporary theme, or have I missed the point?