Complex sentence: The final shot is of the note she left falling off the window just after she has calmly walked past with Joe, then, desperately trying to run back in to put the note back up, only to be carried off by Joe.
Split into simpler sentences: The final shot is of the note she left falling off the window just after she has calmly walked past with Joe. With her desperately trying to run back in to put the note back up, only to be carried off by Joe.