The scissors contains sensors that detect position, and when the red on-screen scissors turns black, it means that there is hair in position to be cut. The scissors also have a built-in motor which attempts to simulate the resistance that you would encounter while cutting real hair.
An obvious use case for this sort of technology would be the ability to give would-be barbers a chance to practice their skills without doing serious damage to someone real-life hair-do.
Air Hair is an ongoing project which much improvements to be made in the future. One hopes that the visual representation on screen will become more realistic down the road, as what we saw looked something like a cross between Kid (of Kid & Play fame) and the rocks at Ireland's Giant's Causeway.
But no matter what way you cut it (yeah, I said it), this early version is certainly a novel idea that will only get better as time goes on.
Here's a short video demo of the Air Hair system in action: