I absolutely love that look on his face, and the "Play with me?" certainly sums him up. I can easily see River trying to get some serious work done, while he's feeling abandoned and wanting her attention.
Very puppyish. And River's rather annoyed, "I'm ignoring you sweetie" as she hunches up a bit and concentrates on what she's doing just says it all.
Aww thank you! He does look even younger than usual here, the silly boy. River probably convinces the TARDIS to blow a fuse while she tries to mark papers, so that the Doctor will do repairs rather than bother her.