I was thinking about what is unique to photography, what can you not do with any other device than a camera. What can be shown with that medium, that no other will achieve? Offcourse you could allways copy a photograph, but that would be no more than a copy.

There is light, shadow and color, projected on a photosensitive surface, that is exposed for a set duration of time. By doing this very deliberately you can see slices of life. "The decisive moment." You can freeze time, by exposing for a short time, or you can go the other way and show movement by exposing for a longer period.

Do you see the motion of the leaves in this image? Sure you could paint such an image, but here the bold brushstrokes of green are done by the tree itself. This image shows how some of the leaves move, while others are still, it also shows how much they move. In a way you are seeing the wind as it expresses itself through the motion of the leaves. I think this is unique to photography.