What is the theme of the story A Summer’s Trade

Which of the following best explains why the author chose the compare-and-contrast structure for paragraph 2

Through actions and conflicts of force, the plot of novel is logically brought to the the turning point in the conflict

[he] let his gaze wander to the swirling water of the stream racing madly beneath his feet. a piece of dancing driftwood caught his attention and his eyes followed it down the current. how slowly it appeared to move! what a sluggish stream! what contrasting words are used to describe the stream in this passage?