"Catenate" is when a series of ties or links connect together, forming a chain.
The study is seen at both day and night, but The Catenate Mall only appears during the latter, actually replacing The Caretaker's Coffin Nails (and giving the wall a second mall story in a row after The Dead Mall, although that has its own problems). The objects in both pictures do actually look alike, a coffin with three nails in it.
From a distance, what is presumably a building is drawn differently to how it looks close-up. It also has a yellow hand from S.A.T.B. Camtempt. Also, when Mr. McKnight and Mayor Corey walk in the door, the words and image of The Catenate Mall's picture (along with the three other pictures) are missing.