What is it with the little guy, that he makes this face when he is concentrating very deeply? When he is in the zone, or working hard at something, he gets all Michael Jordan on us with the tongue just hanging out of his mouth!
Also the scrunching of the face..... furrowed brow and scrunching helps a lot in whatever boyhood work you are engaging in.
(He is actually working at a little archeology toy/game that we bought today.)