Mirrors have existed for hundreds of years. And before then, if people wanted to see their reflection, all it took was to look in a still bowl of water under the right lighting.
No what’s really changed the way we conceive ourselves is the fashion industry, and their advertising, the use a number of tactis to make you think you need ___ product, Or in some countries ___ procedure. From celebrity sponsored brands to unrealistic Photoshopping. To the underweight models on the catwalk.
It’s not just 1 thing that’s made vanity a social necessity, and pushing the idea that natural looks are inherently ugly is just rediculous and wrong.
My sister had her makeup done for her engagement party recently. I had to resist the urge to say my true opinion on it, as she never usually wears makeup that thick and her fake eyelashes just looked out of place. I wasn’t used to it. The moment she ripped them off (with an audible sigh of relief I might add - why you need to sacrifice your comfort for looks makes no sense to me) she looked 10x better, and more like herself.