Lee was pleased with the first two champions, but not so much with Cedric because he wanted Angelina to get it. He was probably commenting to somebody about it whilst vaguely clapping because it's polite. He would be surprised by Harry's name coming out (not least because he knew what happened if you tried to enter your name and you were too young) but ultimately pleased. He likes Harry, and the boy is a Gryffindor as well as being in his social circle. He went back to the common room all excited and was waiting for Harry to come in so he could give him a victory party.