Robot Actors?

So, apparently in Japan they have debuted a robot actress. I initially thought "oh! This will be like River of Gods." Sadly (or fortunately?) I was wrong. The robot is not pre-programed to act, she's controlled by actors back stage. If you watch the video, she seems very fake. She seems more like a robotic puppet than an actress. I guess she could accomplish a certain artistic effect though. If you want one character to be detached and robot-like, why not just use a robot?