The display used a projector to display onto a white table. The chairs around the display were connected with a metal cable, probably to differentiate between multiple users.
The display was controlled by a computer. The Mitsubishi representative demonstrated navigating both specialized computer programs and ordinary Web sites, like Google News. Anyone could navigate at the same time, and the computer sensed which hand belonged to whom.
When I asked if they had plans to make a version of this that did not use a projected image, the Mitsubishi representative said that they felt a projected image was superior to technologies like Microsoft Surface.
Microsoft Surface might have problems with visibility or sensing if someone spills coffee on the table, where a projected image can still be seen clearly. Microsoft Surface is not yet commercially available, so it will be interesting to see how they solve this potential problem.
The DiamondTouch display table did work very well, especially since Mitsubishi was not relying completely on demonstration software. However, having an image projected on your hand did take away from the feeling of futuristic slickness that Surface exuded.