WHBM Smocked Waist Ruffle Midi dress Tan, size s but fits like a medium

Questions? Leave a comment below! size small fits like a medium ( I think ). BELT FROM WHB NOT INCLUDED. I used a different belt, The belt I used is definitely a medium and not a small and not as thick as the belt in the photo ( or as expensive lol) it is a belt from loft. Dress worn only for an hour and I don't see obvious flaws on it. The dress looks baggy in the photo and the belt far too big because the model is my daughter who is modeling the dress reluctantly. My daughter is a size 2-4 and as you can see the dress is falling off her.