I find this picture whimsical. It always make me smile when I look at it. It is one of his many playful tricks, that is hiding when we need to do something to him that he dont like (like change his diapers, clothes etc).
He would hide from us and we pretend not seeing him. He would cover and not move for as long as 3-5 minutes and come out very proud and happy of what he did…probably thinking he can be invisible if he hide his face like that. He also can build a fort made of pillows and hide below it or just a blanket or a big toy like on the picture.