To see it in 3D: fix your gaze on one spot in either left or right image. Slowly cross your eyes until the spot merges with its corresponding spot on the other side. The two images should then lock together in focus, and you can look around the image in 3D. If you have trouble getting the images to align properly, try tilting your head. If you're used to the "Magic Eye" technique, you'll need to reverse the images left to right.