There's something compelling about this throw-away coda, a blank moment rounding out a crucial scene in All About Eve.
Eve (Anne Baxter) has just blackmailed Karen (Celeste Holm) into convincing her husband that she, not Margo (Bette Davis), should get the part for his new play. All About Eve is a film all about "parts:" not hair parts, mind you, or even, as is ostensible, parts in a play. Rather, the reference to "parts" always seems to hover around the idea that primal Eve was conceived from a part of man (Adam's rib). This film, then is about the problem of the "part"--and women's identity with the part or partial. It's also about "replacement parts": above we see a little clockwork machine that is a synecdoche of the whole film. Notice how Eve exits and another immediately replaces her in the woman's lounge, locus of the interminable mirroring of female identity (not that male identity is not likewise mirrored; but many films of the classical Hollywood period tightly link the mirror to woman, duplicity and illusion). We notice the hair: the 'do descending, the 'do ascending, and Margo raking her hand through her own. If the hair-part theorists are correct, Karen is basically reasserting her allegiance to the men of the film, or at least her husband. Faced with the steely ambition of Eve, Karen rakes her hair as if looking for a right part in what is a psychologically more non-committal style, as if to pull herself out of the vortex of the feminine; Karen is a character who easily identifies with and befriends both the male and female characters of the story. Yet Karen's particular form of privileged, diplomatic femininity has gotten her, at least temporarily, into a trap. (Interestingly enough, Eve's more strange and certain hair part is the part emphasizing femininity, even though it gives her a kind of thuggish mien; is it the film's way of saying that her particular brand of ambition is the essence of femininity, and not a characteristic that the men and women of the plot share? Imagine if it were parted on the other side: All About Eve would become something like a cross between Victor/Victoria and Boys Don't Cry. Imagine if Karen had raked her hand on the other side of her head: it would signify that she should maybe get on the boat with Eve before she torpedos everybody in the theater community.)
Karen's particular story is also told, synechdochically, by her smart necklace, reminiscent of so many things, but evocative of her particular brand of strong, but compromised, 50s femininity. The necklace is both phallus and noose, semblance of necktie and, of course, pearl necklace too, with all the rights and privileges that entails.