The fact that this was commissioned explain why nothing but the hairstyle resembles Mordred. The artist clearly does not know the character.
To be fair, that is often how it goes. The tastes of the commissioner aren't necessarily the tastes of the one drawing it. Off course some artists do try to remedy this by doing at least some research of what they're being asked to draw. Like at the very least getting Mordred's eye color and general attitude right.
Mordred for one, I cannot imagine her ever using nail polish.