Responsive Image Hierarchy

In a single column “mobile view”, taller images appear more important than wider images. We came across this unexpected maxim while working on a recent responsive design. Our design employed a ~3:1 hero image with three ~4:3 thumbs below it. At full width it was the proper hierarchy: Biggest == Most Important. However, when resized and folded into a single column, the 3:1 image appears to be about ½ the height of the 4:3 images below it.