the crop top looks stupid on Carys but only because she's not wearing the right size. you can see that the frilly bit doesn't sit against her skin like it does on the other model because Carys is trying to fit into a size 12
but I agree as above that clothes can work on different bodies no matter what size. I wouldn't wear a crop top as a size 12/14 but I've got a small waist (could fit size 10 tops before pregnancy, sizing up if it had buttons etc) and wide hips, so they look stupid on me, but I've seen plenty of bigger people rock a crop top. Sometimes having confidence that radiates off of you as well (and not fake confidence) makes you look better too