This light art is created by a moving display playing an animated image through several camera exposures. In this case the display they’re using is an iPad, but that really doesn’t matter as it’s just a high-quality screen and it’s portable. 3D animations are generated in software and then sliced into cross sections. As the camera rolls, the cross sections are displayed in order and the location of the screen is moved. Very much like light painting with an LED or a Roomba, the bright image remains and can be strung together for the 3D effect seen in the video after the break.
Using the cross sections of the video reminds us of what a three-dimensional object looks like to a two-dimensional being. If you have no idea what that means you should take a look at this video on imagining the tenth dimension.
[Thanks Ferdinand via Flabber]