How does the author use foreshadowing in Talley's Folly?

Talley's Folly opens with the frank revelation that this is a play: the set, which under the proper lighting represents a boathouse surrounded by weeds and trees, is here illuminated by work lights and the house lights, so that the artificiality of the set is obvious. Matt speaks directly to the audience, announcing that the play will run for ninety-seven minutes with no intermission, and that the story will unfold as a waltz, a valentine. If all goes well, he says, the play will end with a romance.