This happens to be a representation of a relatively newer concept in computer systems called a Burst Buffer. I made this to help explain the concept. But, as you can see, what is happening is that the Scratches on the left are waiting and then quickly filling a pool. The pool is then emptied by the Scratch on the right who's job it is to transport the water (the data) to the goal (the hard drive).
Thanks, of course, to MIT Scratch team for the use of their Scratch character.