We played with a 3D setup once for a company i used to work for. If it is the same screen material and setup, this is basically how it works :
For a short while we played with that material. It creates a holographic illusion from a normal projector placed in the roof projecting downwards to a special silverscreen. The holographic semi transparent screen is placed under an angle and this creates an illusion of 3D. It is particularly easy with computer animated images because parts of the image have to stand out more by use of the right contrast.
The projector always project through the semi transparent screen at a silverscreen behind the semi transparent screen. I think It has to do with the image reflected back from the silverscreen to the semi transparent screen adding it with the original image from the projector. The semi transparent screen has properties that when placed under an angle(with respect to the light beam from the projector), it creates a depth perception. It is very important that the silver screen is never seen or the depth illusion is gone.