The robot was built by Nils Völker for the exhibition "Makers & Spectators" at the MU in Eindhoven by Christien Meindertsma.
An eyetracker records the movement of the visitor's eyes. A robot hanging from the ceiling on top of a large pile of paper makes one dot for every point the visitor has been looking at. This results in large scale images showing how the same objects have been seen differently.
More at nilsvoelker.com