When the girls and I picked up Curious George yesterday a handful of kids were drawing. Two of the kids were drawing people, one was making something resembling people, one was drawing a house. CG was drawing this. I asked him what it was and he said it's a water machine. It's a machine with a series of pipes that brings water (and later on, gas) to the house. He said this was for Daddy.
We asked him how he came up with it, and he explained that he sees it in his head and then it goes to his eyes. When the picture is in his eyes, the colors flash and that's what tells him what colors to use.
I'm not an expert, but I think most kids this age draw about what they are familiar with, not abstract stuff.
His teacher thinks nothing of the drawing, but we are very impressed by it. Both Daddy and I are proud. :)