How does Joan Didion use imagery in The Year of Magical Thinking?

Imagery:

"Dolphins . . . had been observed refusing to eat after the death of a mate. Geese had been observed . . . flying and calling, searching until they themselves became disoriented and lost. Human beings, I read but did not need to learn, showed similar patterns of response."

"my impression of myself had been of someone who could look for, and find, the upside in any situation. I had believed in the logic of popular songs. I had looked for the silver lining. I had walked on through the storm . . . [these] were the songs, and the logic, of the generation or two that preceded my own."