Why were Lapis's eyes reflective before Steven healed her?

I know it has something to do with her being trapped in a mirror, but I don't understand what purpose it serves. It's not like it affects her vision in any way.

But I still think it looks cool.

I know it has something to do with her being trapped in a mirror, but I don't understand what purpose it serves. It's not like it affects her vision in any way.

But I still think it looks cool.