She doesn't look like this because this is mostly concept art and the images of her on the map look beautified more than functional.
When Riot designs champions, they have to make sure that what displays on everyone's screens isn't too resource intensive, has the right amount of rendered polygons and that it's very clear at what you're looking at from the usual zoomed-out/zoomed-in perspective. Clarity is a big deal in League since there's 141 champions, followed by a literal metric ton of their assets that have to be displayed on the screens and have to be distinguished enough so that everyone knows from where it comes from and whos attacks/spells those belong to.
Riot can surely render Eve's model in 4k resolution and equally beautify her but to what end?
You're never going to see her delicious belly button sheen caused by the soft moonlight reflecting on her taught, blue-tinted skin. Because it's not possible to zoom in that close and this isn't an MMO. Beautification can only get so so far before what you have before you is more distracting for gameplay purposes than helping.
There's an axiom in almost any other discipline that relates to programming/designing):
If you're sacrificing the ease of use and functionality of a product for the sake of making it more visually appealing, you're making a bad product.
Furthermore, look at Eve's model in-game:
Her base splash is trying to convey that her clothes are actually living shadows and not something that formed "shadowy" fabric that has some rigidity to it. The pinkish glow that comes out of her hair, nails and lasher tips is her own demonic magic. Even the color of it makes you believe that it's inviting, seductive and warm to the touch but that's all a trap for you to come too close to the flame so that Eve can "devour" you.
Everything about Eve is of her own design.
Centuries of adapting to her environment in order to capture her prey in the most unsuspecting way possible. All those details of her splash are faithfully recreated in her base model. Her shadowy clothes are actually moving around her thighs, arms and breasts and convey the idea that she can change her appearance at will and her ornamental forehead flame is moving as well. Obviously, the shadows on her legs, arms, lashers and "lingerie" is conforming to her own shapely form but that's also because she herself wants to project that image of perfection to her potential prey. And if makes it easy for Riot to make skins for her due to having a defined model.
's base skin has been growing on me. The moving shadows are a nice touch.
