GreyZone.... let's take it a step further. It's fake scenery created by the Reader. Isn't this that one of the points that we made in this debate: how the red was being used to pull smoke over our eyes? Even though the red is completely and utterly true (like Erika's EP5 perspective) what is in our "blind spots" we just assume (like the door to the Chapel in EP2 was locked) Kind of like how our brains "assume" what it sees in your actual blind spots. This is things like the the "lock of the Golden Truth" or whatever Will said in EP7. It's not a representation of the GameMaster vs Challenged that's going on, but a representation of Author vs. Reader.
Now that I'm thinking about Reader Theory, I remember a lot of people complaining about Kanon being in the room once Erika gathered everyone together.... but it can be explained using Reader Theory. The Reader reads "everyone was gathered" and imagines Shannon standing on one side of the room and Kanon on the other. What we were seeing was the Reader's infuence. It still violates a more pure form of Knox's 8th though =/