Marjorie judiciously uses hyperbole to give Bernice strategic advice about her lackluster social interactions at parties. She explains to Bernice that even if she’s stuck with awkward men, she must endeavor to make it work to her advantage:
"No girl can afford to neglect them. They're the big part of any crowd. Young boys too shy to talk are the very best conversational practice. Clumsy boys are the best dancing practice. If you can follow them and yet look graceful you can follow a baby tank across a barb-wire skyscraper."
Bernice and Marjorie are in the unfortunate position of needing to find husbands to secure stable futures. By advising Bernice to engage with shy and clumsy boys even if she doesn’t want to, Marjorie is trying to highlight the practical advantages of these dull interactions. Even if the experience itself is unpleasant, Marjorie wants Bernice to remember that shy boys provide valuable conversational practice, and clumsy boys offer opportunities to hone her dancing skills. The hyperbole in Marjorie's statement, particularly the ridiculous imagery of "following a baby tank across a barb-wire skyscraper," is deliberately exaggerated to make a point about the benefits of meeting all sorts of men. If Bernice can do that, Marjorie implies, she can handle anything. This silly exaggeration is supposed to reassure the shy girl, suggesting that mastering the ability to dance gracefully with less skilled partners will help her develop her social agility.
Furthermore, Marjorie's advice implies that being seen dancing with a variety of partners—regardless of how good they are—can only elevate Bernice's social standing. In this world, popularity is everything, and being seen with lots of different men will make Bernice appear more approachable and in demand.
When Bernice finally gets a look at her much-discussed bob, the author employs hyperbole to dramatize her horrified reaction to her new hairstyle:
Twenty minutes later the barber swung her round to face the mirror, and she flinched at the full extent of the damage that had been wrought. Her hair was not curls and now it lay in lank lifeless blocks on both sides of her suddenly pale face. It was ugly as sin—she had known it would be ugly as sin.
Describing seeing the haircut as viewing "the full extent of the damage" amplifies the emotional impact of Bernice's reaction here. Rather than admiring a new style, it’s as if she’s been invited to see a disaster in real life. Through this, Fitzgerald is suggesting she's feeling a level of devastation that goes beyond a mere change in appearance. This phrasing conjures images of an irreparable injury. It’s almost as if she has been physically maimed; she certainly feels as though she has been emotionally damaged.
The phrase "ugly as sin" further heightens the sense of catastrophe. This exaggerated phrase doesn’t just explain the horror and repulsion she feels at the sight of her bobbed hair; it also reflects the fact that cutting it was her choice. She has “sinned” against her traditional understanding of femininity by chopping it off, and the result is that she finds herself “ugly.” This further reflects her deep insecurity and the societal pressure she feels around her looks as a young unmarried woman.