I have written that fiction that includes passage into an instance of unreality highlights the perspective of the passenger, thus emphasizing an element that makes the travel metaphor seem particularly apt. There are exceptions, such as the shifted passage technique, which has the function of verifying that passage has actually happened in the world of a fiction (in our examples, these fictions were all movies). But on the whole, the perspective of the character who makes the trip is closely attended to.
A further characteristic that is sometimes in line with the travel metaphor and sometimes not is this: the character who does the trip sometimes fully departs from his world, vanishes physically, and at other times remains there, albeit oblivious of, and incapable to interact with his surroundings for the duration of the trip. In order to have some labels, let's say that a character sometimes leaves his world in the mode of ejection, and at other times in the mode of projection.
Thus in the clip from Die Einsteiger we have a clear case of ejection: the two travelers vanish from their own world for the duration of their trip. Shifted passage is used to demonstrate this to the audience; but the fact is also often referred to in the course of the movie, when the trips get more and more extensive and some characters even decide never to return from the fictional worlds they have entered. In contrast, in Dreamscape we have seen a typical example of projection (the word 'project' is actually used in the film itself as a term for the act of entering dreams of other people).
Entering dreams or memories seems to suggest projection mode more than ejection mode, perhaps because it allows closer modeling on the (real) dream state, which is very similar to projection: you're asleep, you physically remain in your room, though oblivious to your environment, and the only sense in which you're 'there' in the dream world is mentally, even though it may not look and feel that way to you while you're immersed. On the other hand of the spectrum, trips into fictional worlds and time travel seem to suggest ejection more strongly. (In particular time travel stories would struggle to use projection mode: it's rather counterintuitive to suggest that a character can be a two different times at once, whatever 'at once' can mean in this context. Remember that all passage stories, time travel not excluded, have to keep up the metaphor of traveling, and that requires a sequential personal time for the traveler, even as she jumps from one spacetime-location to the other.)
There can be hybrids: in the extract from Sherlock Jr. the protagonist doesn't simply enter the world of a movie, he dreams that he enters a movie. So we have a more complicated setup: there is the world of the Buster Keaton movie itself, then nested inside it the world of the dream, which allows passage into movies, and then again nested inside that dream world the world into which he steps when Buster walks into the movie screen. The latter is a clear case of ejection, for the in-dream-Buster vanishes from the world surrounding the movie screen when he walks in. But then there is also the dream itself, which is a case of projection. (The sleeping body of the projectionist remains visible for us, the audience, unresponsive to the surrounding world, but not physically away.) Probably the motivation for this complicated setup was a hesitation to make the movie too phantastic. It's one thing to create a fiction in which people dream (not unusual in the real world, too), but another to create one in which people walk into fictional worlds through a movie screen. (To wrap the more extravagant elements of a fiction into a dream is a time-worn device, just think of the epilogue of A Midsummer Night's Dream.)
Note that there is no difference in the experience of the passenger between ejection mode and projection mode. The passenger is immersed in what happens at the destination location. The only difference is what an additional observer would see at the origin location during the time of passage.
Yet shifted passage neither implies ejection nor projection. We have seen ejection in the clips that included shifted passage, but as I have noted, there could easily have been shifted passage in Dreamscape, where we're clearly in projection mode. Likewise, in The Dutch Master, there's no shifted passage, which I argued is by design; yet both ejection and projection might be in play here — the movie leaves it open, thus allowing both interpretations, but this very fact shows that there might be both cases in which we have no shifted passage and projection and cases in which we have no shifted passage and ejection. So the distinction between use of shifted passage or not on the one hand and projection mode vs. ejection mode on the other are completely orthogonal.