Because there is no documentation on the topic, let me explain what I did just in case it helps someone else. First, the problem is in the module style selection. The gk_photo option just crops the image at the bottom for no understandable reason. I suspect that is a bug because you cannot expect a designer to change every image and pad it with blank space. All the other styles from the other templates work without doing this to the image.
I used the gk_bikestore option which got me to something closer to what I wanted. But none of the options provide the desired solution because photo resizing only works in the horizontal axis of the browser's width. This means that if the width is great, the image will scroll past the bottom. I would like the aspect ratio to also calculate the vertical direction so that the image is guaranteed to display in full no matter how the user elects to size their browser.
The suggestion to not generate thumbnails was a very good one, but for an entirely different reason. My next issue was going to be image quality. Not generating thumbnails fixed that issue. That probably should have been the default but now that I know I can live with it.