Well, humans are the only species gaga over mammary glands. It always amazes me to find what people find beautiful. I would say that one component of beauty is derived from the health parameters. Now that part makes sense, because mating with someone healthy equals to healthy offspring. The other part is derived from social perception. Like kind of peer pressure. Because social agreement will get you more peers and for humans the grouping is important. This is the part the fashion industry encash on. Now there could be a thrid part to beauty. Feeling the awe when you see aura lights for instance. But why would looking at a malnourished homo sapiens female make anyone feel awe? So that doesn't make sense either. Only thing I can think of for the beauty in question here is social agreement on beauty. And it is weird that men trying to have standards on what to find beautiful because they are not even that choosy naturally when it comes to mating preferences. I can't think of a good reason for sexy daughter hypothesis, the counterpart of sexy son hypothesis.

A good example of social pressure is also skin colour. For instance for a long albino kids were looked upon as evil in some African tribes. Then about 8000 years ago as genes for white skin swiped through Europe, there was a reversal in what colour they found beautiful. Now a part of that can be attributed to advantage of being white in cold artic regions. But finding the same thing beautiful in topical regions like India is what fairness skin cream companies encash on. And the social pressure is once again manufactured by popular idea perpetuated by those who benefit from it.

Like what the hell has skin colour to do with dream job of being a good reporter or TV anchor. But watch this ad