What is that strange Bear scene in The Shining about (and is it a bear)?

The "bear scene" is a brief moment in The Shining when Wendy, beginning to see the same "1920's Party" events that Jack's been seeing, is wandering through the halls of the hotel. As she looks around a corner, she sees two shapes huddled over the edge of a bed. As she looks, they are revealed to be two men, possibly engaged in oral sex. One is wearing what looks to be a bear costume.

The scene is taken directly from Stephen King's novel. In one of the novel's scenes set in the 1920's party, Jack is dancing with a beautiful woman. He notices that at one table, there is a young man behaving like a pet dog for the amusement of others, including a tall, bald man.

The bald man is Horace Derwent, a Howard Hughes-like figure who poured millions into restoring the Overlook Hotel in the 1920's. (Jack has learned this by reading a mysterious scrapbook earlier in the novel.) The younger man has a romantic crush on the bisexual Derwent, and Derwent has said that 'maybe', if the man dresses like a nice doggy, and acts like a nice doggy, he 'may' be willing to sleep with him.

Later on, in the novel, as Wendy is warily navigating the corridors of the Overlook, she begins to see the visions of the 1920's party. And at one point, peering around a corner, she sees the two men on a bed, one in a doggy costume. The two men are Derwent and his extremely dependent lover.

It's difficult to say why this second scene remains in the film; as it's somewhat confounding without all of the set-up that King provides in his book. Perhaps its jarring incongruity is reason enough for its inclusion, illustrating as it does Wendy's extreme disorientation at that point in the film. Another explanation is that the background on Derwent may have been scripted and filmed, but excised in the final cut.

All work and no play makes Jack a dull boy