I had a different interpretation of the body language. Having gone to a majority black high school, I immediately recognized Obama’s expression as what I would call, pardon my French, the “Dayum” face. As in “Dayum! That’s a fine booty”. Sarkozy likes it too, but he is playing coy, with a wry smile and his finger to his lips as if to supress himself from saying something that he is thinking. Black guys just tend to a bit more expressive than the white guys when they see something they like.
Obama bears no relationship to ANY black man I ever known.