The "overture" and "exposition" have the same role within a narrative text, or in a prose. This is because these two terms refer to an introduction to the plot of the story, where the characters will be presented, the scenario and even the main subject of the narrative.
Top-left: Wealth worship. The landlord is so impressed and intimidated by the bank note that he barely dares to take it.
Middle-left: Impending doom. You can tell that the narrator is experiencing a sense of upcoming catastrophe through phrases like "I judged that there as going to be a crash." The situation the narrator is in also involves danger: "I must swim across or drown."
Top-right: Rags to riches. Taken literally, this expression means going from the poorest to the wealthiest one possibly can be. But in this context, it is more about 'social riches:' the character goes from being insignificant in the eyes of others, to widely influential.
Middle-right: Wealth worship. The landlord is willing to accept any of the narrator's whims simply because he is wealthy, but at the same time, he fears him and his power: "he hoped he wasn't afraid to trust as rich a gentleman as I was."
Bottom: Impending doom. The threatening danger here is expressed by the fact that a "thin crust" is all that keeps the narrator from falling into the crater.
