There's a lot of stuff in it that wouldn't easily translate to the screen. The saddest thing is that Stanley friggin' Kubrick, who everyone in the industry believes is one the greatest film makers ever, didn't even try most of the time. When he did it was just a bunch of quick screwy random images: the skeleton ballroom, Jack seeing the maze turn real, the elevator of blood, Jack in the vintage photo. This is the random junk that lesser film makers throw into their movies to give the impression of a deeper meaning.
I think he was far too influenced by great actors. He did everything Peter Sellers asked him to in two movies. Once it was clear that the audience would love every second that Jack Nicholson was crazy on the screen, there would be no need to waste time for a subtle transformation. The Making Of showed how much Kubrick was enjoying Nicholson's performance.