Sariel has got artificial-looking violet hair, black lips (lipstick?), yellow cat-like eyes and black marks, tatoos (but likely it's her skin color), all over her body. Apparently she is naked, but the marks covers her body at few places, like: face (mask), torso (breast and collarbone), hands (gauntlets), groin (pants-like), legs (high boots). She's slim and feminine, maybe due to her in-game class - she's a mage, not a warrior, who usually physically developed. Thus, she uses mages stuff.
At the art picture she looks a little bit different: two horns and elves ears appeared, hair became bob-like, collar appeared on her neck, the marks slipped from the collarbone to the breats only, and the "boots" became even higher than before.