As above, so below
If we're comparing the women, the comparison would've been fairer if the model had been smiling. But as Henrik and others have noted, the designers don't want us looking at the model's face (or other, ahem, attributes), but at the dress.
So, what used to be a large T-shirt is now an XL, so why is it suprising that a normal sized woman is now a plus size?
Please dont hurt me...
STARGAZING: All I see are the lights of a billion places I'll never go. --Howard Tayler, Schlock Mercenary
Well, you're a het- man, presumably.
I don't know if it's acculturation, or their wiring, but women* just love frilly, colorful, impractical garments.
It's probably cultural; upper class men dressed quite differently a few centuries ago.
I don't begrudge all fashion, some of it looks nice, but most of it looks like aesthetic abominations--the clothing equivalent of Brutalist architecture.
*Of course not all women. Bless the tomboys and geeky girls.