We like to feature creative photos over editorial type photos. Looking through previous issues is a good way to see what we like, and so is the Flickr group. It's hard to give an exact answer because there are a few moderators and it just has to be something that gets our attention.
Anyway, here are just a few of yours that I love:
http://www.flickr.com/photos/light-shades/4607457649/
http://www.flickr.com/photos/light-shades/4620155402/
http://www.flickr.com/photos/light-shades/4534959904/

You can also check out our photographer faq:
http://positivexposure.com/faq/photogfaqs/