Guy Hoffman gave this talk about how to design, build and study robots that communicate with people.
One of the robots he built is a robot light, which can respond to what happens in the environment. With the same mechanical structure, at one point, just by the way it moves, she seemed gentle and caring, helped Guy finding things he was looking for; and in the other case, seemed violent and confrontational when someone was yelling at her.
Moving in a graceful way is just one building block of this whole structure called human-robot interaction. Guy then used animation tools to build robotic musicians who enjoy music by moving their bodies and tap their foot when music started.
Video source: youtube.com, Ted