The best description I've ever received is that this can be, for your loved one, too stimulating, too much change. It is the equivalent of shaking their personal snow globe. And I got that advice from a friend whose hubby had, what was thought to be, EARLY ONSET, but turned out to be lewy body.
However, I think it is true across the board with anyone with dementia. I've seen it with my mother, and with others.