It seems that if you're tall these days, you're also supposed to be a lard ass OR an anorexic emo kid.
Being skinny really doesn't help much either. I have the same build as most mannequins (which is kind of disturbing, but that's just the way it is), however, the clothes they put on them are deceiving because they're always pinned or clipped in the back. It's kind of ironic and a little annoying that clothes aren't even made to fit the way they're displayed and advertised!
Having worked in retail, that's not done to try to mislead you on how things fit. It's cause the size that actually fits the mannequin is one generally one of the sizes that sells out first.