This picture clearly represents a woman's face even though there is no outline of a head. The only features are the eyes, eyebrows, nose, and mouth, and that's all we need to conclude that it's a face.
A Realistic Lip Painting Tutorial by Packwood on Deviant Art packwood. *NOTE, not my art- simply linking so other aspiring artists may use the tutorial for learning. I own no rights. You can use the included link to go to the original page.