I saw the pics of the photo taking. Michelle is the one who appeared royally pissed off, so I would guess you are disgusted with her open display of disgust. She looks genuinely angry.
Seeing the most important people in the world acting like giggly teenagers is perfectly fine some of the time, as it makes them look human. Doing it at a solemn event might be a tad tacky, especially knowing that photographers were capturing every moment. Imagine Bush doing this at, say, Pelosi's funeral or Kennedy's and then ask how it would have looked.
Shaking hands with an evil dictator with blood on his hands is Obama's choice. If he wants to be friendly with Castro and aid in the propaganda in Cuba that will come from the handshake, so be it. We don't have to be impressed. These events are planned to the last detail, as is any appearance from the pres, so he chose to be friendly and he can deal with those who find it offensive.
I realize that the left would prefer that we pay full attention to Obama sometimes and look the other way, without comment, other times. Forget it.