Watch or fast forward to the part of the movie when TS and Brodie first encounter Willam Black. Willam is staring at a Magic Eye poster trying to see the hidden picture. He can't make it out, while Brodie and TS immediately realize the picture is of a sailboat.

If you freeze frame on the actual Magic Eye poster, and if you are able to see the picture in the poster, you'll realize that it ISN'T a sailboat at all, but rather three or four rows of geometric shapes: Stars on top, spheres in the middle, and triangle wedges pointing toward you on the bottom.