During the dinner scene in A Clockwork Orange, the level of wine in Alex's glass varies from shot to shot, and it was claimed that this was intended to create a disorienting feeling. I think it's more likely that the insane perfectionist in Kubrick couldn't stand it when this flub was noticed and just had to provide a reasonable explanation.

That's just my thought on that movie, it might be true as far as The Shining goes.