She can see herself in third person.
A slight lean of the eyes turns her against the starry background; focusing, or something like focusing, adjusts the lighting conditions from soft to stark to dim to blazing, warm to cool, dappled to spotlight-simple.
Does she like what she sees? If she doesn't, it's easy - tempting, like picking at a frayed fingernail - to change it. Clear skin? Nudge cheekbones? Color hair? Sharpen teeth? Lengthen legs? Dye eyes? Add fingers - change cup size - smooth cellulite - sprout feathers - flatten tummy - embed crystals - armor shoulders - manicure nails - illuminate bones - grow wings - incorporate tail -
The changes feel like nothing on their own. It's like adding drops to a glass in her hand: she can't feel the impact of water on water, but she can tell it's getting heavier, and can tell where the minimum fill line is - but not how heavy it can get before it will slip from her fingers.