The Party
The key to understanding Kubrick's final shot of The Shining is by focusing on the 'party' element of both the film and the novel. In the book, Jack regularly comes into contact with characters and stories about a masquerade ball led by long time deceased and previous owner, Horace 'Harry' Derwent. The link between book and film here; Lloyd is the bartender at the party, Grady is there also. Both men in both versions seem to gravitate to the party. And the party is cited as the heart of the Overlook's wickedness in the book;
"A long and nightmarish masquerade party went on here, and had gone on for years."
The last part of that quote is interesting, as it establishes a sense that something has been ongoing in the hotel for a long time, and shows no signs of slowing. The "party" is most likely not identical to, but rather a 'cousin; of one that Jack is pictured in at the end of the film. So far, so glaringly obvious, and it is likely that even the most disinterested of you had figured that from watching the film. But stay with me for a moment...