How does Joan Frances Casey use imagery in Flock: The Autobiography of a Multiple Personality?

Examples of Imagery:

"Watch them flutter in swirling confusion and then, abruptly, move together in perfect formation again, each knowing its part in the whole. That's what I mean by group minds."
Chap. 20, p. 155

"Kendra and I were then forced to take turns. A switching of pen from hand to hand was more acceptable than two pens writing in different scripts simultaneously."
Chap. 27, p. 213