In Irwin Shaw's short story, "The Girls in Their Summer Dresses," there are several uses of symbolism.
First, as the story progresses, we learn that Frances is desperate to keep her husband close, even as she senses him moving away—as he watches every attractive woman they pass. Frances announces that she wants to keep Michael to herself for the day, but this is simply symptomatic of a deeper concern. The image of a "rope" symbolizes how Frances needs to feel connected to Michael—even to hold him against his will:
"Also, I slept all night, wound around you like a rope."
The fact that Michael is gaining weight may be symbolic of a deeper change, a movement toward a more self-centered lifestyle that comes from indulging his whims, and does not include Frances. However, Michael's response when she notes that he is "getting fat" and she loves it, seems to indicate that he resents her "worship" of him: a lack of self-respect on her part whereby she will take whatever he dishes out (to a point) and be happy for it.
"I love it," she said, "an extra five pounds of husband."
"I love it, too," Michael said gravely.
Michael does not seem to appreciate this "devotion," perhaps feeling the challenge of wooing and winning his wife's affection (after five years) has left him feeling unfulfilled. If so, the challenge of gaining the attention of other women may appeal. Michael has obviously put a lot of thought into his constant "oggling" of women:
"...the handsomest women, out to spend money and feeling good about it, looking coldly at you, making believe they're not looking at you as you go past."
The summer dresses that Michael refers to (as this husband and wife walk in November) may "represent freshness, youth, and vitality," while reminding Michael of his approach to middle age, and a sense of loss he may experience in that women don't respond to him in the way they did when he was younger.
As with other stories by Irwin Shaw, this one touches on the theme of lost or disappearing youth.
Michael may be caught up in the past—when he was part of the game he witnesses all around as they move along. In not feeling as connected to that part of his life, Michael watches women and "wants" them, doing so in the presence of his wife—showing how little regard he has for her feelings, and how strong his desire is to please himself.