It's hard to pinpoint exactly when Jack Torrance starts to lose his mind. In fact, there's enough evidence to suggest that the process began long before he ever got to Colorado. While Wendy and Danny explore the (impossible) maze, however, Jack looks down on the scale model and experiences, what? Megalomania and a feeling of omniscience, perhaps, or is he imagining bringing his giant fist down on them, of 'correcting' them?
The cut to the interior of the maze is a rare mismatch from Kubrick, as Wendy and Danny have already reached the second set of benches in the long shot. Or have we just taken a step back in time? The temporal is rather flexible at The Overlook Hotel.