Why Does Huxley Cut Back and Forth in Chapter 3?

In chapter 3, Huxley cuts back and forth between the Controller; Lenina and Fanny; Bernard Marx and, intermittently, Henry Foster and the Assistant Predestinator; and Sleep Teaching (Hypnopaedia).

Each of the characters and exchanges represents a key thematic issue.
What are those themes? And what purpose does the juxtaposition of those themes serve.

Please address:

Mustapha Mond (the controller)
Lenina and Fanny
Bernard Marx, Henry Foster, and the Assistant Predestinator
Sleep Teaching

When reading each of the events, it made me think like it was all in a movie. Sometimes you're at one scene, and then you find yourself at another. The scenes could even be happening at the same time, just in different places and situations.
I think Huxley is (possibly?) trying to test if we're paying attention to the story or not, because we're getting a look on how their world was made, what civilians do in their spare time, and the benefits? of sleep teaching and soma.

I agree, Denyce, with the notion of the cut backs seeming movie-like. I do not, however, think that Huxley is testing us. The juxtaposition of these passages suggest a relationship among thematic elements in the novel, all of which Huxley explores in the rest of the book.

So... kind of like foreshadowing?

Yes, although I am not sure if that is the correct term, in this case.
Motif, maybe?