Well, a bit of fridge logic, but why do the girls that are visible all have the same body/bust type? I'd expect Applejack to be more bulky or even visibly muscular, Rarity to be slimmer and more "elegant" than "voluptuous", Rainbow to be short and DFC like Tomo from Azumanga Daioh, and Twilight to generally be smaller as well.
It's also strange that Pinky has the most notable eyelashes when Rarity is the one that has the comically exaggerated lashes that almost look like whiskers at times.