When we take trips together to photograph things, we are often in exactly the same location, yet the resulting pictures are often vastly different from one another, sometimes making you wonder whether we in fact visited the same place or not.
I love how Bill put it above, that "I believe photographs document relationships between subject and photographer". Those relationships are always colored by the photographer's personality, education, intelligence, perception, instinct, experience, ability, and many other traits of their personality. How we all see things, even as viewers of the same photograph is very interesting.
Do this exercise some time: Make two identical prints. Have two people sit in front of that same print and study it for a few minutes. Then ask them to close their eyes and describe what they saw. It is with quite a bit of certainty that what comes out of their brains are different things, colored by their own experience and frame of reference.