1. It looks like it converts into a freakum dress.
You shouldn't be able to see a short club dress hidden under your long evening gown.
If you like the look of these kinds of lightweight, sheer evening dresses, make sure you choose one that has enough going on — like pleats or abstract prints or embellishments — so that whatever is underneath doesn't show through. If the sheer fabric being used is too simple or flat, it will seem flimsy, and that's never an expensive look.