Images abound in this novel. Start with the very first line of Chapter 1: "Ships at a distance have every man's wish on board." Wow. That makes wishes into cargo—into physical objects. A bit later, there's this great line: "The sun was gone, but he left his footprints in the sky." This creates a very vivid sense of how the sky looked, but also of how personalized their world was. Finally, from the same paragraph: "Mules and other brutes had occupied their skin." This combination of an almost sterile word—"occupied" with an image like possession creates a dichotomy.
As far as Janie, the imagery gives a sense of the world in which she's traveling, and of the distinction between men and women.
Hurston is known for her use of poetic imagery in this novel. Focus on her descriptions of Janie's hair, which is usually meant to symbolize her womanhood and, at times, her independence. Another notable use of imagery is the pear tree, which symbolically marks the beginning of Janie's journey into womanhood and is strongly linked with her quest for the horizon - for what's "out there" in her future. The imagery surrounding the storm at the end is also very powerful and can be analyzed strongly in terms of a character vs. nature conflict.