I am of the opinion that all these containers are the same size and shape. In the car on the right you can see containers next to each other, crosswise and lengthwise. It's clear to me that the width is about 2/3 the length. Furthermore it's clear that containers are narrow enough to fit two across the width of the gon. And as you can see from the gon on the left, there is actually room in the gon for 12 containers. But apparently with the material being loaded, the weight is such that a single gon is rated to carry only 11 containers. So put 4 over each truck, to minimize stress on the gon body,stacked as closely as possible, that is paired paired side-by-side. Then put 3 more in the middle. How you put the three in the middle is optional. put them more or less evenly spaced but crosswise, like the car on the right, or put them as if you were loading 12, except put the last one centered, like the car on the left.
The foreshortening from the photo is about what you would expect at this angle. You can get more confidence about this by looking at the first crosswise container next to the 2nd lengthwise pair (L to R) in the right car. You can see that the length of the crosswise container is a little less than the combined widths of the two containers next to it. That matches the view of the width being 2/3 the length.
Tom Hayden