Of course the next panel in that sequence is happening in the real world and would show you,
the reader, sitting with the latest Superman issue in your hands, deep within the Infant Universe of Qwewq in the Fortress of Solitude, today,
wherever you are. In “Neverending,” the reader becomes wrapped in a self–referential loop of story and reality

とあるからフィクションと現実で無限連環構造になってるのは間違いないかと