unicorns!! specifically, rarity!!
in the polar opposite direction as pegasi, i think that unicorns would envision 'beauty' being decided by either how magically gifted you are. or, in rarity's case, how close you are to looking like a de-winged alicorn!
more than pegasi or earth ponies, i think that unicorns would hold the alicorns in extremely high regard, and set the majority of their beauty standards up against them. a unicorn is attractive based on:
1) how tall they are
2) how powerful they are, and
3) how distinctly their colouring sets them apart from the crowd while still looking clearly like a pony.
as a rare white unicorn w an incredibly stark purple/blue mane, rarity has the third in spades, along with the first due to her ancestral relation to felines.
while not having the sheer magical power of twilight, rarity has incredibly refined control that lets her levitate a large amount of different objects without ever making a mistake. i.e, controlling needles, spools, measuring tapes, and bolts of fabric while using the sewing machine at the same time.
this is all to say. the world is very very lucky that rarity became a seamstress instead of a model, bc the world would've been extremely screwed!!
oh!!
rarity had a bit of a wild youth in her teen years. she subscribed to the philosophy of 'work hard, party hard', and probably still would be if her friends weren't so allergic to canterlot!! one day she'll get fluttershy and applejack into a nightclub, mark her words!!
