There are other giants down in the mall.
The statue was originally part of an entire showcase. At one point if you look closely while Wyatt is running, you can make out what looks like shadowy figures in the distance.The underground mall wasn't built down there.
Rather, it was teleported underground by currently unknown forces. The fact that the exits are marked, just blocked off with stone, seems to imply that those exits were originally above ground and able to be properly used.The Mall is akin to a sentient location like The Overlook Hotel.
It does at least tick some of the boxes. Like the Kubrick film's impossibly large hedge maze behind the hotel, the mall is inexplicably "underground". Once the mall has a desirable visitor, the place powers on and the music starts playing, much like the Colorado Lounge. Once The Mall deems Wyatt a suitable Caretaker or whatever, the main exit gets sealed off and the Mall starts toying around to welcome Wyatt, The Rolling Giant being a favorite tool to toy with him much like the animated hedge animals in the book version of the story.- As for why Wyatt's body was ejected back out to the wilderness, maybe that's so rescuers think he merely just died, not realizing there's more to his fate. Wyatt may now be tending the Guest Services desk with Ghost Amnesia, like Lloyd the Bartender, and offering services to unsuspecting wanderers to do the mall's bidding.
- Jossed as of Dispersal as Wyatt is sent back in time to the moment before he made his treacherous walk across the structural beams, and successfully made the leap into the stairwell this time to complete a hasty escape up the stairs. However, as Wyatt drives away, it is implied that the Rolling Giant is somehow following Wyatt to his next destination, suggesting that the Giant has an interest in Wyatt.
The mall and its entrance is A Glitch in the Matrix, a glitchy moment in time that was accidentally copy-pasted into an underground space.
Wyatt discovering the mall created a problem in maintaining the secret of the matrix, so an editor somewhere sealed him inside and essentially played Jigsaw with Wyatt for morbid amusement. Wyatt's body was then moved back to the tree entrance, and presumably the entrance tunnel was sealed off completely. Of course, this leaves questions like why Wyatt was allowed to go back inside the mall to begin with...- The architect presumably brought Wyatt back to life as they didn't want to upset the balance of the reality by having him appear dead spontaneously, but the Giant following Wyatt back might turn a few heads unless people can be convinced that the Giant is a remote-controlled prank.
