Move the egg-head observing and imagining how facial traits change, as if the character is looking one way or the other.
Observe how the character's eyes would continue at the same height and the nose and mouth parallel to them.
Observe how facial traits move from one side to the other, exposing one cheek completely while we can barely see the other.
If the character looked up, observe the way in which its eyes would bend. Observe how its chin would seem bigger and its forehead smaller.