Question on Item Preview Image Size

I had a quick question about the item preview size of 1600x800.

Why so large? I don't think there is anywhere that I have seen on the site that uses this size of image and I just noticed that the smaller images are resized to the larger size then compressed back down for the page display.

I don't mean to be nitpicky, but can the admins shed some light on why this image size is used? Would it be possible (in the future) to have an auto-resized version that more closely matches the size of the image on the item page?

Looking at this further, it looks like the images are stored as preview.jpg, but are used as preview-xl.jpg on the item page itself.

I'm mostly wondering why the extra large image would be used here as opposed to the standard preview which is much closer to the image size being displayed. Maybe this is a holdover from a previous design?

The large image support is for retina displays which displays at 2x the resolution of a normal display. The high resolution version is only used on the item page itself.
The 800x400 image (preview.jpg) is used in product listing pages and various other pages and feeds.

If you have any other questions, just let me know.

Thank you for clearing that up, it makes more sense now.