Cosmetics: are they useful or do they just make us feel good?

“…the Darwinist approach to attraction – beautiful faces and well-formed bodies are important biological indicators of a person’s value as a sexual partner.”
A Darwinist approach would be biologically based and modeled in other species. In other species, mate preferences develop via associations with social odors: olfactory/pheromonal cues of reproductive fitness. Food odors and social odors activate the same evolved neurophysiological mechanisms in all mammals. How might we have come to prefer beautiful faces and well-formed bodies if not via their association with human scent signatures?