Time And Space
In the book, Jack figures that time and space are irrelevant within the hotel walls;
"In the east-wing ballroom, a dozen different business conventions were going on at the same time within temporal centimetres of each other."
And
"a fire?...in August?...yes...and no...all times are one."
And
"Then the party had begun again (or did it ever stop? Did it sometimes just drift into a slightly different angle of time where they weren't meant to hear it?)"
This idea that all things happen in a continuing present, raise the idea that the party at the Overlook is a signifying source of its contemporaneous nature. So in Kubrick's focus on that party; by harnessing and recreating details of this over other elements from the book, he is demonstrating the same theories of time and space...
Back To The Party
A key player from the party scene in the book is a man known as Roger. He appears in the book dressed as a "dog or wolf", and he shares a very special (hinted; homosexual) relationship with owner and party master, Derwent.
"...Harry never goes back for seconds...and Roger is just wild. Harry told him if he came to the masked ball as a doggy...he might reconsider..."
This man is described in the book a little further;
"To the left of him was a dog's or wolf's head...the mouth open in a meaningless snarl...between fangs that appeared to be papier-mache."
Sound familiar?
Although both characters are not a perfect match to their literary counterparts, they are, when compared to these extracts, extremely close. After all, the slight discrepancies could be put down to Kubrick's inane changes throughout; Wendy is not blond, an axe replaces a roque mallet, Halloran has no tight afro, the miniature Overlook becomes a hedge maze. Either way, the presence of these characters draws further closeness between both mediums and their focus on the party. This is key to my theory. The party is central. Kubrick's focus on that means it has relevance. But it doesn't quite yet explain the final image of the film...
Joining The Staff
However, some answers can be found in the book, when Wendy tells Danny;
"The hotel caught Daddy."
We know that this means the Overlook in King's book has the ability to absorb anyone who allows it, into this eternal and timeless party; which, if we accept Kubrick's particular adherences to the novel, suggests upon death, Jack is "caught" in the film as well. It would explain why Kubrick purposely chooses to include Grady's phrase from the book;
"You're the caretaker, sir...You've always been the caretaker.",
as it further cements this idea that once you become part of the hotel you have been, are and always will be a part of it...even if that means paradoxically you have not yet joined it. And further more, it shows why Jack is at the front centre of Kubrick's final image. Originally you might put this down to a logistical aesthetic; it being easier to spot with Nicholson in that position. However, if Kubrick were indeed subversively feeding the character of Jack from novel to film, he would also be focusing on Jack's obsession with being of "managerial timber." In the last third of King's novel, Jack becomes increasingly obsessed with replacing the mysterious 'manager' and running the ghostly Overlook himself;
"his last and best chance; to become a member of the Overlook's staff, and possibly...all the way to the position of manager..."
Suddenly, it becomes clear. Jack in Kubrick's version has become a part of the Overlook, and has got himself all the way to management. That is why he is placed where he is in the image. Time is one. All is now. Jack is there. But he was then. Once he became a part of the Overlook, he became its legacy. That is why the picture is on the wall. It would have been there long before the Torrence family arrived at the hotel, and it remains after they left. It was destined to happen because it has and did. If Kubrick had burned his Overlook to the ground as King did in the book, then Jack's ghost would have died with it. But because changed the ending and his Overlook remained, the Jack in his version manages to obtain what the Jack in King's version never did. And that is the mark really. That is a likely reason why Kubrick made all the miniscule changes that he did; to establish his version of The Shining as an alternate reality. This exists in the same universe as King's version, but it is a different story. That is why there are no killer bush animals or wind up clocks, but the Donner party get a mention and Jack is a frustrated writer. There is creative licence vs thematic emulation. In spite of differences, the party is a constant. That and 'Redrum'. And we see that connection between the two worlds when Wendy, in a fit of fear, bumps into a grinning dead man; who rhetorically declares,
"Great party, isn't it?"
Murder. Ghosts. Parties. Time. The four linking elements that suggest what exactly Kubrick borrowed from the book. And four things in the book we can clearly understand...