>>9594833Nah the comic also has two holes, one in the seafloor (which is the robot's chest) and one inside the dome where Voya Nui used to be, on the Southern Continent, below which is Karda Nui. The art just does a bad job making it clear because the art in the 07 comics is generally unfathomably terrible.
This is not reflected in the original concept art, where Voya Nui's core was a plug in the robot's armor that shook loose when the robot crashed. In the old concept art, there is only one hole directly above Karda Nui, and the Southern Continent doesn't exist at all. This was later changed in the actual story.