Question re 'Atonement' - movie vs book

I am wondering something about a certain difference between the book and the
movie, both entitled "Atonement". It concerns the sequence of the events as
depicted in the book and then in the movie.

My question concerns the scene when Cecilia jumps into the fountain to
retrieve the broken parts of the vase. I seem to recall that in the book
that scene was shown first. After that, I recall that the book then
described Briony observing that the event from the window. My question is:
"Am I recalling this sequence correctly?"

In the movie, the sequence of the events was the opposite of the sequence in
the book, as I recall it. In other words, in the movie the scene where
Briony observed the event from the window came first. The scene showing the
actual event by the fountain came next.

Perhaps it was necessary to show the scenes in this sequence because of the
nature of film, as opposed to the written word. The written word can explain
so much more. The movie must present the story mostly in pictures
(especially in scenes without dialogue) and that necessitates a different
approach.

I suppose that most people wouldn't wonder about these seemingly
insignificant matters. But it's details like this that can often make a big
difference, especially in a story with such a labyrinthine plot.

---Sea