Some details
The clip of Bush is from his surprise visit to Iraq.
Note the shirt, and somebody in the video says "Welcome to Anbar." This information is not made clear in the video. Under the circumstances, a wildly enthusiastic response would be expected.
Obama's apparently making a formal visit to Camp Lejeune, and the audience might be expected to be on formal behavior.
I have heard some people imply that both videos took place at the camp. Not true.
Apples and oranges.
