The diagrams remind you what form of logic you are using to tell your story
Each diagram form represents a different form of logic, either a grouping of ideas or a deductive argument.
The grouping diagram visually reminds you that you are constructing a list of independent ideas that together aim to support your overarching conclusion.
The deductive diagram visually reminds you that you are building a story with a series of three dependent ideas. The sideways connection of the boxes shows this interdependence.