One of the things that seems most powerful about a photograph is its ability to capture the ephemeral. It reveals the essence of a certain place or person in a moment. That moment becomes an eternal pause, allowing our eyes and mind to contemplate a reality that might not have be visible without the camera or photographic medium.
And perhaps too, that is why it is so difficult to create the photograph that lasts. All things must come together at once: light, subject, composition, and the magic if a specific moment, frozen in time.