How does Nadine Gordimer use imagery in Jump and Other Stories?

Imagery:

"The curtains are open upon the dark, at night. When he gets up in the morning he closes them. By now they are on fire with the sun. The day pressing to enter. But his back is turned; he is an echo in the chamber of what was once the hotel."

"He swam a great deal. far out in the calm bay between wind-surfers crucified against their gaudy sails, closer in shore where the surf trampled his head under hordes of white waters. A shoal of young mothers carried their infants about in the shallows."