In my opinion, the great characters not only interact with the guests that are up for the photo/autograph on a personal level, but are also able to make those interactions a bit of a "show" for the other guests waiting. Of course, this is easier for the face characters, but the furries can do it too. For example, I recall seeing Gaston interact with a young girl in a Belle dress. The interactions were so precious that it became a bit of a "show" for everyone else waiting in line. Everyone was smiling, and I'm willing to bet that, at that moment, none of them felt that "hurry up, I've been waiting" feeling.