What does that expression mean ?

The New York Times ( Sunday 18th July ) reports on machines that can conduct teaching by recognising the facial expression of the computer user.

Research at the University of California recognises facial expressions to determine whether a child is enjoying, or understands an activity.

Eyes widen.

Carey, B & Markoff, J (2010) Reading, writing and robots. New York Times ( articles selected in association with the Observer, 18th July )