It was soooooo high school - or maybe college frat boy stuff. People who think they're "oh so cool" often do that type of smirking - it's dreadful.
I'm surprised you didn't see it. A few minutes after I made my comment, Juan Williams of FOX News made the same comment and even used the word "smirked".
Obama acted like a junior high schooler. The smirks, the grimaces, the rolling of the eyes - and the downright rude interruptions - were straight out of 8th grade.
Barry came across as having been heavily coached without understanding what he was saying (hence the “block answers”), he spouted a cloud of generalities, and he was obnoxious and immature in his personal manner.