I'm always interested in how photo editors make their choices in sifting through photographers' work on return from an assignment, as an example. From a PDN's article, I learned how a Travel & Leisure magazine photo editor made the choices for a "South American Haciendas” story, photographed by David Nicolas.
Out of the 10 images in the PDN article, 5 were rejected and all of these were verticals...is that a coincidence? That's why I constantly try to photograph horizontals and verticals as much as I possibly can...provided what I photograph lends itself to both. I'd hate for an editor to look at my submissions and say "hmmm...you have that one in vertical (or horizontal)"? Elementary perhaps, but still worthwhile remembering.
I still think photo editors write their own rules, and have their little quirks.
PDN's Making The Final Cut