The great thing about this pic is it totally shows what everyone likes to point out. Ben creates a character completely separate from himself. The only connecting factor is he is the actor playing the character. And it is times like this pic that show it. You never see sherlock with this look on his face. This is a moment if Ben shining out from behind the costume and being himself.
John...just look at him. He's just like "God, why am I stuck watching these children?" If it were Kid!lock he'd be the older teenage boy who always ended up babysitting Sherlock, Moriarty, and Mycroft<< honestly, this makes me laugh so much!!!