Near the start of the novel, while bantering about whether or not writing poetry for your romantic partner adds to the strength of a relationship or takes away from it, Darcy uses a metaphor comparing poetry to “the food of love,” which Elizabeth challenges:
“I have been used to consider poetry as the food of love,” said Darcy.
“Of a fine, stout, healthy love it may. Everything nourishes what is strong already. But if it be only a slight, thin sort of inclination, I am convinced that one good sonnet will starve it entirely away.”
While Darcy engages in the conversation very earnestly, sharing a metaphor about romance, Elizabeth has already formed her prejudice against Darcy and instinctively pushes back against what she likely reads as a lack of playfulness combined with upper-class posturing (this is an allusion to a line in Shakespeare’s play The Twelfth Night, after all).
Rather than agreeing that poetry is a form of expressing love in a budding relationship, Elizabeth jokes that it can actually lead to a decrease in romantic feelings. This moment of conversational sparring establishes the dynamic that will continue between them for much of the first half of the novel, with Darcy seeking connection with Elizabeth and Elizabeth turning him down, refusing to trust his intentions or character.
Near the end of Elizabeth and Darcy's dance together at the Netherfield ball, Elizabeth brings up Wickham, and their conversation becomes tense. Before parting, Darcy uses a metaphor to ask Elizabeth not to let her prejudice against him develop further, and Elizabeth builds off the metaphor in her response:
“I can readily believe,” answered [Darcy] gravely, “that reports may vary greatly with respect to me; and I could wish, Miss Bennet, that you were not to sketch my character at the present moment, as there is reason to fear that the performance would reflect no credit on either.”
“But if I do not take your likeness now, I may never have another opportunity.”
Here, Darcy uses figurative language to ask Elizabeth not to “sketch” his character (as an artist might), and she continues the metaphor in her response, suggesting that this may be her only opportunity to capture his “likeness," the way an artist would. Darcy uses this metaphor because he is aware that she is making judgments about him based off of the rumors she has heard from Wickham, which Darcy himself knows are not true. Elizabeth’s response indicates that she feels comfortable drawing conclusions about him based on Wickham's stories, which she later comes to regret, as she discovers the kind and caring man that Darcy really is.
This metaphor also adds to the layers of innuendo in the ways that Darcy and Elizabeth speak to each other, as is required by the manners of the time. Rather than directly accusing Elizabeth of developing a prejudice against him, Darcy alludes to it in this roundabout way so as to appear cordial and nonchalant.
After Elizabeth rejects Collins’s marriage proposal, Mr. and Mrs. Bennet approach her to talk about her decision. Mrs. Bennet makes it clear that she wants to force Elizabeth to marry him anyway, while Mr. Bennet uses a metaphor (and sarcasm) to explain his feelings on the matter:
“An unhappy alternative is before you, Elizabeth. From this day you must be a stranger to one of your parents. Your mother will never see you again if you do not marry Mr. Collins, and I will never see you again if you do.”
Here, Mr. Bennet uses a metaphor—Elizabeth becoming a “stranger” to one of her parents—in order to communicate that he and Mrs. Bennet are at odds about her decision to refuse Collins’s marriage proposal.
Unlike Mrs. Bennet, Mr. Bennet actively supports Elizabeth's decision not to marry Collins. Mr. Bennet also uses exaggerated language in an attempt to add humor to a tense situation. At the same time, though, his metaphor acknowledges the impossible position Elizabeth now finds herself in, ultimately recognizing that whatever decision she makes will essentially alienate her from one of her parents.