In the opening pages of the story, what details of setting, of characterization, and of dialogue foreshadow later events?
Let's look at what happens at the end of the story in order to better analyze how the opening paragraphs foreshadow those events. Mrs. Crater and Lucynell are sitting out on the porch when Mr. Shiftlet shows up. Mrs. Crater hires him as a handyman, and he is very taken with the car that they own. Mrs. Crater makes a deal with Mr. Shiftlet. If he marries Lucynell, he can take the car with enough money for a honeymoon. Mr. Shiftlet agrees, and he marries Lucynell that Saturday. On the way to their honeymoon, they stop at a diner, and Mr. Shiftlet leaves Lucynell and drives off.
I think there are two important details in the opening paragraphs that foreshadow this sobering ending. The first is that Lucynell is practically blind and has some kind of mental handicap.
The daughter could not see far in front of her and continued to play with her fingers.
She is not physically or mentally able to "see" what is coming and what kind of person Mr. Shiftlet really is. To her credit, readers can't really know at this point in the story either, but O'Connor drops a really big hint when Mr. Shiftlet turns and holds his arms out wide.
He turned his back and faced the sunset. He swung both his whole and his short arm up slowly so that they indicated an expanse of sky and his figure formed a crooked cross.
His figure formed a crooked cross. It's not even a broken cross because of his arm stump. It's a crooked cross because Mr. Shiftlet is a crooked and wicked man. He's not an upstanding citizen. What's great about the foreshadowing is that Mr. Shiftlet then actually announces his tendencies to be shifty, crooked, and "rotten."
"Nothing is like it used to be, lady," he said. "The world is almost rotten."
A good question.
Consider the first statement about the daughter: " The daughter could not see far in front of her and continued to play with her fingers."
She can't see far ahead literally—but she can't see what's coming either.
When discussing Mr. Shiftlet, O'Connor gives us this line: "He held the pose for almost fifty seconds…" He is a poseur—one who poses, or takes on certain positions. He means to deceive. He then drops the pose, as he does in the larger story.
Of course, my favorite line is Shiftlet's: "Nothing is like it used to be, lady," he said. "The world is almost rotten."
Nothing is like it used to be—the mother used to be young, have hope, etc.—but the key point is that he tells us the world is rotten. He's rotten, and will do lousy things.