http://computer.howstuffworks.com/mind-reading-computer-news.htm
Here's how it might go down if the robot reads the following faces...
- "Happy human, happy robot"
- "Very happy human, very happy robot!"
- "Playful human, playful robot"
- "Confused human, worried robot"
- "Unhappy human, unhappy robot"
- "Mad human, mad robot, kill all humans!"