

why is the upper shadow placed right on the lip line?
trying to analyze yana toboso’s art rendering and I really loved this picture on disney+!! So when I focused on it I was confused by the lip shading. It’s so mind blowing how professional artists know where to add highlights or shadows because that shadow placement would have never crossed my mind haha
But I really want to understand why there is a shadow drawn ON the upper lip? I somewhat understand the shadow below the lower lip but not on the upper lip.
Alsothe light source comes from the top right, correct? If so why is there a bit of highlight on the back of his hair?
Could someone explain the light logic behind all of this?:)