Nice idea, it might find some quirk of the face detector though, and exploit that, instead of producing a truly face-like image.

On the other hand, I vaguely recall a talk by VS Ramachandran where he claimed that in essence that's what Picasso and many others did also, i.e., you might see a painting that objectively doesn't strongly resemble a face, but it hits the right spots in your brain's face detector, so your brain says to itself "now that's what I call a face". A bit like how colorful candy triggers "ripe fruit - eat it!".