How does Julius Lester use imagery in To Be a Slave?

The words of those who actually experienced the anguish of slavery create a vivid, wrenching historical account. These narratives contain most of the book's symbolism and imagery. In the following passage, for example, an ex-slave describes the frustration experienced by newly emancipated slaves—who faced restrictive laws, economic oppression, and the Ku Klux Klan—in terms of a metaphor: Two snakes full of poison...".The snake called slavery lay with his head pointed south and the snake called freedom lay with his head pointed north. Both bit the nigger and they was both bad."