She is 100% wearing that corset upside down AND backwards!!!! I’ve worn that exact style of corset for a couple musicals I’ve been in. The lace up part goes in the back and the part she has lazily hooked once at the top goes in front. The part that’s sort of winging out at her hips is where the boobs go!!!
I actually found the exact costume on Amazon. See how the hooks are in front and the laces in back?
Edit: lol someone commented asking if it was upside down and backwards and she replied “lol no”!!! 😂