How does Jack Finney use imagery in Time and Again?

Imagery:

"... the sense of wonder, staring at the strange clothes and vanished backgrounds, at knowing that what you're seeing was once real. That light really did reflect into a lens from these lost faces and objects. That these people were really there once, smiling into a camera. You could have walked into the scene then, touched those people, and spoken to them. You could actually have gone into that strange outmoded old building and seen what now you never can - what was just inside the door."