screen 1 screen 2
/ \
/ \
/ \
mm <- hand
\ /
torch 1 torch 2
Now any movement of your hand changes both images in a correlated way. In a
sense, the images are entangled - if you observe image 1 to have a certain
configuration, then only a small subset of possibilities in the total
configuration space of image 2 are valid, and vice versa.