Based off of these comments, using the same logic, Evelynn would be reflective of what is culturally accepted as desirable?
And if so, why does she shape-shift then? I'm confused.
I wonder what her current form is supposed to represent, my guess is Demacia. With all the "justice" and "honor" and what not, you gotta bet that behind closed doors, they're probably into some kinky shit.
I'm not a lore expert but to end the debate in the comments it is stated evelynn CAN change her form herself, but she chooses not to due to something about how difficult it is to perfect it.
For example Urbino Venus and Beatrice Chenchi are beautiful even with the sense of modern people.
And yet at an earlier time, it was JohnODyin who said (paraphrasing) Evelynn couldn't really shift form instantaneously. That if Evelynn wanted to change appearance, it would apparently take decades to settle into a new more perfect form.
Vastaya and Evelynn and possibly 
( illusionary) have been confirmed shapeshifters for a while, but now that 
is released it's gotta be toned down because shapeshifting is her thing.
Evelynn is a demon and demons don't really have a physical appearance.
They pretty much confirmed the same thing about 
(who also looks different depending on the region) already
