Currently its difficult to view panorama images. The thumbnail, small, medium, and large sizes are all too small for a typical panorama. I think viewers have an expectation that panoramas will take longer to view, and posters have an expectation that these images will take up more space in their account. So I think it would be desirable to make these images larger for easier viewing.
The problem seems to be that images are resized according to their longest dimension. My suggestion would be to determine if an image is a panorama by checking whether one dimension is, say, 3 times longer than the other or more. If so, then size the images according to the smaller dimension. For example, for a horizontal panorama, make the "large" image size be 500 pixels tall and let the width dimension fall where it may. Medium could then be something like 300 pixels tall, small 200, thumbnail 100 for example.