Complex sentence: DC Comics designed special covers based upon some of their most classic editions to display in the Other Side and these, and other popular culture differences, were noted and appreciated by critics causing the writers to add more of them in the third season.
Split into simpler sentences: DC Comics designed special covers based upon some of their most classic editions to display in the Other Side. These and other popular culture differences were noted and appreciated by critics, causing the writers to add more of them in the third season.