I had posed this question over at Flickr and Shiv Prakash Got it right. There were two LCD projectors one projecting the yellow dots and the other projecting red crosses with over lapping projection area. The arms seen are the left and right arms of the model respectively and are not mirror images. The setup gives some very cool effects by changing the angle of projection and the distance of the model from the screen. See the set up below!
Feel free to ask questions or leave comments