Tell it sistahs!!
Most people are just not well-informed enough about how to dress for their body type to say no to these "trends" when appropriate. I would not wear something like this unless the alternative was nakedness. And perhaps even IF the alternative was nakedness. My butt is too big - that skirt would be tenting right off of it, making my butt look even larger than it in fact is. A similar effect would be achieved by the tenting off of "the shelf" with that shirt.
Similarly, I would also like to see the extreme low-rise thing END. I am not asking for pants to sit at the waist. That too is unflattering. But this very low-rise thing is terrible. There is an undergrad who works in our lab. She is beautiful, thin, you know, 19. Anyhow. She sometimes wears these low-rise jeans where the butt pockets are placed too low (because when the rise is THAT LOW, where else are you going to place these pockets?) and it makes her look like she's got a saggy ass. When of course, she doesn't. I really just want to take her aside and explain this, but I don't think that would go over well.
When jeans can make someone like this undergrad look dumpy, you know there's a problem.