The head is a solid — the silhouette is its outline, morphing from a rounded rectangle through an egg to an organic blob. Drag the stage to spin it.
Style picks the house the eye is drawn in; Realism then walks that house’s own range. The rows with a link on them drive both eyes at once — unlink one to set L and R apart, or click an eye on the stage and drag it.
The resting face. There is no mouth, so the eyelids do the acting — how far they cover, which way they slant, how high the lower one arches — and the gaze, the head and a squash of the body agree with them.
What it does when nobody is touching it. Idle wanders and fidgets; the rest are acts it keeps up until told otherwise — it still watches the cursor and still reacts to a slider through them.
Personality rather than looks: how loose the line is, how much baby the face borrows, and how it spends its attention.