I think theatrical is an apt way to describe it. I learned the technique in a staff training many years ago. The speaker's name was Michael Brandwein. He came from a children's PBS programming background and has developed techniques for all age groups. I've since participated in multiple training events with Mike as the speaker. He's been an excellent resource for me personally. I do think a bit of it comes down to acting. Take an actor like Jack Nicholson, for example. Next time you watch a Jack Nicholson film, pay attention to his face. His face is always moving. I've found I can make my face a visual target. I try to make eye contact with my students. Even if I break eye contact, they continue to follow my face. In return, I can visually track who is paying attention. If someone is looking down or away, I move closer and get them to make eye contact. I ask questions. I respond. They watch my face and I can usually get them to maintain their attention. I also think exaggerated expressions lighten the mood. It definitely has elements of both comedic and dramatic effect.