Ho, ho, ho
The boys are playing Santa. A chair is the sleigh, various toys are, well, toys, and a set of blocks laid out in a line extending from the front of the chair are reindeer. Right now they're arguing about who gets to fly down the chimney into Bethlehem and give baby Jesus his presents.
(Yes, I know it's January, but Christmas is a pretty intense holiday, you know? It takes a kid a few weeks to work it through.)
I'll bet baby Jesus will be thrilled with his gifts, though: from his infant perspective, a block, a toy airplane, and a red crayon have got to kick the prosaic ass of gold, frankincense, and myrrh.