I don’t know what kind of function you feel must exist there, and feel like the desire for that function comes from not really understanding the purpose of each tool. The function that unifies them is you, the writer, using each tool as you step through the writing process. A helps you do one kind of thing, that you need to do; B helps you do another kind of thing, that you also need to do, and that you need to do after A.
What does that mean? Well, how would you start playing a chess game before the board and pieces were in front of you? Answer: you wouldn’t. Even if it were a mental game, first you’d have to have a mental board.
Some of this ties back to the real world. You want to guys in a ring swinging at each other, trying to knock each other out.
Okay. First, where’s the ring? In Harlem or in Vegas. Are these black guys, or white, or one of each? is one tall and one fat? Is one a great fighter, expected to win, the other short and a former murderer. See all the potential I just set up? But no conflict yet, and no action, just description. I’m charging the story. I’m doing it for the audience, because I’m a storyteller. So think of the setup as a gesture of consideration for the audience. You can just throw two automatons swinging at each other, but isn’t it nicer if we pretend they’re real people in a real place? That’s what that painting at the beginning is all about.
If you set up the pieces on a board, it’s a chess game, otherwise it’s just pushing uncarved wood across a table, and who cares.
So, the function? Necessity. First this. Then, and only then, that.
How I do go on.
At some point, I promise you, a light will go on. It is natural that it doesn’t at first because you are learning something hard, and that deserves respect. Good for you.