How does the author use imagery in the novel, Wonderstruck?

One example of imagery can be found in the scene where Ben stands at the window reminiscing about his past.

"He watched the clouds roll in. He thought about the times when the aurora borealis, the northern lights, appeared in the night sky. Everyone along the lake would call one another, no matter what time it was, so they could watch the strange shimmering curtains vibrating above them."