From the Painting Guide: Anyone who's a migraine sufferer will identify with this painting. (It'll be interesting to be able to compare it to a portrait without one!) I feel that the chaos of the hair emphasizes the thundering inside the skull. And that the portrait fading at the neck echoes the way a migraine makes you feel physically disjointed from the world around you. The use of color and tone, the deep-set eyes certainly convey a sense of pain endured.
Things to Consider When Looking at This Painting:
Shadow: The pupil and white of the left eye seem a bit light given the color of the other eye and the shadow in the eye socket. Don't be afraid to loose detail in shadow; it's surprising how little of a suggestion of form there needs to be for the viewer to be able interpret it. Squint at the picture and you'll see how the left part of the face becomes a powerful, dark shadow. Carry this over onto the left ear by adding a touch of the purple there.