How is the symbol of loneliness represented in "The Chrysanthemums" by John Steinbeck?

The symbol of loneliness is the clump of chrysanthemums Elisa carefully pots for the tinker to take with him. When she later sees them lying in the road, unceremoniously dumped with the pot missing, it is disheartening to her, and the reader understands the depth of her loneliness.
Elisa and Henry live a fairly isolated existence on their farm in the Salinas Valley. Even during the relatively slow period just before the harvest, Elisa and Henry go through their days separately; she busies herself in her flower garden while he attends to business matters. Elisa is described as full of energy; it is clear that she is not entirely fulfilled with her life. The windows are "hard-polished," and the "mud-mat" is clean; with "terrier fingers," Elisa dispatches any garden pests around the chrysanthemum shoots.
Even though there is little reason for the reader to think that Elisa is unhappy with Henry and their life together, it is significant that she takes an inordinate interest in gaining the tinker's admiration. She indulges him by giving him some dented pots to repair, though it is clear to the reader that she does not consider it a necessity. Only after the tinker feigns interest in her flowers does Elisa soften and give him the pots. He listens as she has pours out her heart about her expertise with the flowers, and she takes him at his word that he will deliver the plants and her instructions to his next customer.
The fact that Elisa has taken such care to pot the chrysanthemums makes the tinker's callous disregard for them all the more poignant. Elisa has reached out to make a connection: first with the tinker and then to the woman to whom he has promised to deliver them. The sight of the discarded flowers underscores Elisa's isolation as she turns back to Henry on their way into town.