Do they actually expect guys to be able to tell a 5mm difference, never mind 2? This feels more like social commentary of the fashion industry.
Also remind me of this old webcomic... girl's freaking out that her boyfriend's going to dump her because she gained 5lb. Next panel, he's standing there going, "Duuuude, I think her boobs got bigger!"
Edit: Oh. Whoops. Thought it was a .5/.2mm difference at first. Okay, half a cm is easier to see...sort of.