I was looking for help with a puzzle on youtube and noticed a few video segments that did not appear in my game. Most notably in the library with the telescope puzzle, there's a video that shows all the guests talking about strategy that didn't play in my game. Do the videos change depending on the order you do the puzzles in?

There should be a point halfway through the game where no new rooms are open; at the point, you should experience that video in the library, which acts as a flag that unlocks more rooms. Unsure why it isn't triggering for you, though.

Ah, you're right. That scene showed up after I played a little longer. Thanks.

No problem; also, the most easily missed FMV will be in the kitchen now that the library scene has triggered.

The non-linearity of house exploration unfortunately means you'll see the FMV sequences in an unintended order, or even miss out on some sequences entirely. For example, you can explore the kitchen at the beginning, but you're not supposed to solve the maze and coffin puzzles in the cellar until late in the game, otherwise you won't understand the FMV sequence that plays out down there.

Yeah, I thought I was missing scenes as well, but I think my memory was just playing tricks on me due to the order I was encountering the puzzles.