What causes us to think a certain thing is “beautiful”?
The current media has a lot to do with what is perceived as beautiful. Standards of beauty fluctuate as time goes by. For instance, what was beautiful 10 years ago isn't necessarily what everyone has the hots for now. Currently, Instagram culture has a firm grip on the standard of beauty.
The popularity of people like Kim Kardashian (who's made millions of dollars selling that faux sense of perfection) has brought about that heavily contoured, long haired, curvy bodied Instagram model "look". It's bits and pieces of what most men have stereotypically liked over the years into one "perfect" Build-A-Bear esque woman.
People see the attention surrounding Kim and the success she's had, and they want that for themselves. What ends up happening? We have an app full of women that all look like her, with millions of followers at that & even making a career off of it.
So, basically, it all depends on what the media's focused on at the time. If we were never introduced to Kim Kardashian through many media outlet's heavy obsession with her, maybe today's standard of beauty would be entirely different. I'm certainly ready for it to shift.