So the question is why among humans it is typically the females that wear sexy clothing, accentuate their breasts, wear jewelry and paint their faces with cosmetics. The display situation seems to be reversed from most other species.
Which culture? Which period? Have you seen much of fashion through the ages?
http://www.sirclisto.com/cavalier/costumes.html
And clothing is relatively recent: before it became the norm, men scarified their bodies, painted their faces, wore elaborate headdresses... and still do!
http://creativefan.com/tattoo-ideas-for-men/ Besides, physical decoration isn't the only sexual display. Most birds have to win a home-site and many must build a nest, before they can even go courting. Bison and moose, elk and mountain sheep all fight one another for the privilege of mating; felines and canines all have to prove dominance over their male competitors and defend a territory; simians have to be smart as well as powerful. From age 5 or even younger, human males show off to human females, in season or out, whether the female is receptive or not.
My speculation (that's all it is) is that among humans, it's still the males competing among themselves by making the bigger displays. Except that among humans, the male competitive displays are behavioral. Males compete with each other to appear richer, more powerful, more successful and (yes) smarter than other males. That kind of male behavioral competition might well be one of the evolutionary features of humans that has contributed to their extraordinary success as a species (as well as to no end of conflict).
The latter part, yes, possibly ... though I'd like to posit that it was in larger part due to intelligent co-operation.
In either case, there is no essential difference between the competitive displays and behaviours of humans and other social animals: it's about reproduction, as well as power, status, a better chance than the next family, the next clan, the next tribe, the next nation, at personal survival and genetic continuity.
I'm inclined to speculate that historically, sexual disparities in intellectual life might be an outgrowth of that. Males might be more driven than females to make displays of their intellectual prowess, thus motivating them to produce ideas, books and art works at a much greater rate.
Most of this activity would have been directed at the advancement of the individual in his own tribe (status, privilege) and also the ascendancy of one's own tribe over its rivals on all sides. Women's necessary contribution to this effort was aid and comfort for the ambitious husband and the production of lots of little peasants and soldiers.
Remember: until very, very recently, all this intellectual activity was restricted to something like 1% of the males; the rest were engaged in manual labour and had very little autonomy; few had the opportunity to display their mental attributes.
It isn't that females have lacked the ability to be creative intellectuals, it's that they were less driven to devote their lives to the effort.
It's that most of them never had a spare minute to devote. A very few high-born ladies of several different cultures did indulge in intellectual and artistic pursuits, and were accomplished in various fields. I'm inclined to agree, though, that they were probably less competitive and secretive and clubbish than their male intellectual equals; more likely to share information and innovation with their community than to hoard it for reward.
The largely Jesuit-driven European educational agenda of the last 600 years before, and most of the way through the Industrial Revolution deliberately obfuscated the names of accomplished women in all areas of endeavour. Which, of course, brings religion back to the fore. The one most of us are familiar with has been actively misogynist from its inception.