In this passage, as Bernice sits frozen with horror in the barber’s chair, the author uses a simile and allusion to depict the dramatic change in her appearance after her questionable haircut:
Her face's chief charm had been a Madonna-like simplicity. Now that was gone and she was—well, frightfully mediocre—not stagy; only ridiculous [...]
The simile describing Bernice's pre-haircut charms as having "Madonna-like simplicity" refers to the traditional depiction of the Virgin Mary. This biblical figure is often alluded to as a way of bringing up ideas of beauty stemming from gentleness and purity. This comparison underscores how Bernice's long, dark hair previously helped enhance these qualities in her appearance. When her face was surrounded by thick dark hair, she looked serene and endearing in a way that is similar to the “Madonna” trope.
No longer, however. Her new dramatic haircut, a flapper-style bob, is the aesthetic opposite of this allusion’s relationship to traditional femininity and the purity that people often associate with it. Rather, the bob suggests sophistication and a certain bold worldliness. This style starkly contrasts with the innocent and simple visual impression that Bernice made before. The allusion emphasizes the unsuitability of the new haircut for Bernice. It’s not just unflattering, it actively clashes with her natural demeanor and physical attributes. Instead of adding to her beauty, she feels the haircut renders her "frightfully mediocre" and "ridiculous." Before this, she and others around her felt that her inherent simplicity was her most attractive feature. The bob prevents that from being immediately visible, making her seem very distant from her "Madonna"-like, pre-bob image.
In this passage—which takes place as Bernice and Marjorie go to bed after the disastrous haircut—the author uses similes to make Marjorie’s long blonde hair seem especially luxuriant:
Then Bernice winced as Marjorie tossed her own hair over her shoulders and began to twist it slowly into two long blond braids until in her cream-colored negligée she looked like a delicate painting of some Saxon princess. Fascinated, Bernice watched the braids grow. Heavy and luxurious they were moving under the supple fingers like restive snakes [...]
The first simile describes Marjorie as looking like "a delicate painting of some Saxon princess." The Saxons were a Germanic ethnic group who lived in Europe in the early Middle Ages. In the public imagination of ancient times, Saxon women have pale coloring that includes rosy cheeks and wheat-colored hair. By saying she looks like a “Saxon princess,” Fitzgerald is evoking an image of corn-like, fairy-tale blonde hair that gives Marjorie an almost mythical beauty. This imagery contrasts with Bernice's bob, which doesn’t have any of these qualities. To Bernice, Marjorie now possesses a kind of femininity that she herself has so reluctantly given up.
The second simile compares Marjorie’s long blonde braids to "restive snakes," suggesting they are so thick and long that they’re like living boa constrictors. When Bernice was getting her hair cut, she was suddenly very aware of its weight and heft. Watching Marjorie style her own hair reminds Bernice of the physicality of what she has lost. These similes collectively show the reader how deeply Bernice has sunken into envy. The luxuriousness of Marjorie's braids as she prepares for bed only deepens Bernice's feelings of inadequacy and longing.
