From Tom Chandler:
Zen Tip #2: Compose your pictures in two dimensions – as if you were painting them
This is might be the single most important Zen photo tip you’ll ever read (as if you’ll ever see another Zen photo hints article).
Most amateur photographers make the same mistake; they pick up their camera and look through the viewfinder (or LCD screen) instead of composing pictures on it.
The principle at work is simple; you’re building an image on a two-dimensional space the same way a painter arranges objects on a two-dimensional canvas.
If you pick up a camera and start looking through the viewfinder (or LCD screen), your eye focuses only on the principal object of the photograph. The inevitable results is a dead-centered, too-far-away, boring image.
Next time you’re shooting, take a second (and a deep breath), and look at the viewfinder like it was a frame around a painting. Compose your image within the confines of that frame, and yes, take a minute to move the frame around the subject.
What you’re doing lies at the heart of the process; you’re not taking a snapshot, you’re composing an image [emphasis in the original].
That made me understand the point very clearly. Thanks, Tom.