Steinbeck uses in vivid imagery, which sets up the contrast between Eliza's "light" and the "grey" that consumes her world. The land parallels Eliza's isolation, both mentally and physically.
In the first paragraph, the narrator says,
The high grey-flannel fog of winter closed off the Salinas Valley from the sky and from all of the rest of the world. On every side it sat like a lid on the mountains and made of the valley a great closed pot.
The following paragraph also contrasts Eliza with her environment:
It was a time of quiet and of waiting. The air was cold and tender. A light wind blew...but fog and rain do not go together.
Like the farmers who hope for rain, quiet and waiting, so too does Eliza bide her time, hoping that some supernatural event will deliver her.
Steinbeck also uses metaphors, frequently comparing Eliza to a caged animal as she goes about her tasks. Trying to rid her beloved gardens of weeds, her anger and frustration are taken out on the troublesome intruders:
"Her terrier fingers destroyed such pests before they could get started."
Also consider how the language Steinbeck uses reflects the absolute control with which Eliza tries to order her world. Her house is "neat," the windows "hard polished"; even the "mud mat" is spotless. But desire and love is lacking in her life, and out of her control. Watch how many times the color red appears, a symbol of passion.