NOTE: the textbook and many places of the web site give a wrong spelling for 'Parrhasius'. (There are a lot of mispellings 'out there' and our source was wrong.) The corrected spelling is based on the most authoritative-looking sources found doing a comparative study through Google. The problem is, probably, the transliteration from Greek script.
These unpronounceable Greek chaps (Zeuxis — "ZOYK-sis" and Parrhasius — par-AS-ius) actually hold the keys to the inner secret of art — that the audience's expectations are central. You've read the book, so you know the story. Two painters, both experts. One depends on his technical skill with paint, the other on his knowledge of what human beings are like. Parrhasius painted a curtain, which was what the audience expected to SEE, but they didn't expect that it would be a false curtain. So, while Zeuxis was able to fool a bird, Parhassios was able to fool not just humans but EXPERT humans at that!
The set-up of the wall will help you adopt to the REPRESENTATION-ARTIFACT angles. Here's the diagram that you'll find in the textbook:
The right angles "tell you everything" about how Parrhasius's trick works. Instead of operating in the dimension of representation, it is flat up against the vector of the artifact (the curtain against the wall). This reminds us just how unsuspecting the audience is when artifact is used. The audience is used to forgetting about the artifact, of enjoying the ILLUSION of the work of art. This kind of focus makes them vulnerable.
Learning to think in terms of abstract models and diagrams helps you see the things that are "meant to be invisible" in art. The backstage tricks are what makes art seem effortless to consume and enjoy. The tricks work hard so that the audience won't have to. "Vectors" are used in scientific and engineering thinking to represent forces that have specific direction. The artistic use of vectors is very similar, because the forces that hold art together also need to operate in specific "directions" — that is, spatial and temporal contexts.
The artifact/representation distinction is very important in the next chapter, "The Aretha Franklin Theory of Communications." See how vectors there work in a very literal way to hold context and noise at a "distance" from conventional communication. In art, this "distance" is shortened. By the fourth chapter, you should begin to see the connections. It's not easy to grasp at first - so much new material and a different way of looking at art. The best way to get into it, of course, is bring your own experience to bear.
Another good practice is to re-think all ideas you've encountered to date. Don't forget the wheel of fortune, the system of humors, or the whole "contract" idea (displacement, surplus, collation, levels). You can tell the whole Zeuxis-Parrhasius story in many different ways. Imagine that the audience reaches an "anagogical" realization when they discover that it's THEIR OWN assumptions that have made Parrhasius the winner!
Make sure you use the DICTIONARY on the web site whenever you run into a weird unknown term. That's not often in this class, eh?