I think empire waists can look either really good or really bad, depending mostly on whether or not they get narrower under the boobs, and then on how "flowy" the fabric is. If they just hang down from the boobs, then yes, they cover any potential extra flabbyness, but they also often make people look pregnant. But in cases like the dress two posts above and Edith's shirt, they look pretty damn good, and they can also help hide some belly without making you look pregnant.