Something suggests that the face is seen from an angle and yet something else suggests it is seen from the front. I'm not sure what it is though. Maybe the lighting and shading and the positioning of the pupils or the shape of the eyes... maybe someone else can tell, I can't, all I see is that it looks kind of strange.
The pixels themselves and the dithering is all well. I'd maybe darken the backdrop to separate it from the facial color and also shade it more aggressively (more contrast, darker shadows, also on the sides to give some depth). That's all just in theory though, I don't know if I could pull off those changes, so please take this just as a suggestion by someone who is himself still learning.