One thing my wife learned and told me (she’s a biologist so actual science vs my CS background :) ) was actually fairly interesting and is apparently widely considered true among evolutionary biologists:
If you are male of you are likely to carry genes from your father that produce a similar appearance to him. You will /also/ carry genes from your mother that prefer your appearance (your mother choose your father based on appearance). If you are female offspring you will inherit those same genes but won’t express the male appearance ones. You will still pass them on to your offspring.
So you end up with a cycle where offspring look like/prefer the appearance of their parents, and will forward variants of those genes on to their own offspring.
This is effectively a feedback loop that will carry on until limited by some other factor - eg if your tail is too long you may end up dying too quickly to mate, if it gets too small you may not be able to fly at all (some of the old pigeon breeds studied by Darwin are hilarious).
This means that the selection for beauty does not necessarily mean that there’s an awareness of fitness being proxied by beauty.
Once she had labouriously explained it to me it seemed really obvious.
* note I used male/female etc for ease of typing - there are a few species where the role of being attractive is reversed