Darren had a great post on this in the DPS blog,
http://digital-photography-school.co...n-photography/
Basically I take it as an image that has one real point of interest, that doesn't even fill up a full third of the image, and the rest of the image is a standard texture, so you know what the focus is and aren't distracted by the background elements. But this is just how it registers in my mind.