Some of the philosophical concepts that are discussed here are difficult to grasp for a lot of people. I think M.C. Escher brilliantly illustrates the subject-object conundrum in his drawing, "Prentententoonstelling" (1956) (Print Gallery).
In the illustration Escher masterfully employs the Droste effect.
Some of the people at Hendrik Lenstra of the Universiteit Leiden and the University of California at Berkeley made it a project to visualize the mathematical structure of Escher's illustration. Through the mathematics, they've been able to fill in the whited-out center dot. It is a spiraling repetition of the illustration.
They even made animations in MPEG and AVI file formats of the illustration. You can set Windows Media Player on loop and see the repeating spiralling effect.
[URL=http://]Animations of the filled in print[/URL]