Thanks so much for the detailed answer. I am going to digest this and try to set up my portraits accordingly. I did set up some small sample images of customer finished photos by extending the canvas of the original images, and included them at the end of some of my galleries. I understand now that the galleries are actually landscape oriented.
I can't afford to distort people portraits, or crop them too much, so I will have to extend the canvas in Photoshop, to have the black area on the outside. This is an example of what I did so far. index.php?gallery=1&theme=dark