Uploading an image does not only strip exif data!
Animated gif files will be reduced to the starting image, so the animation of a background gif file does not work anymore.
The need of uploading an image for use as background image might have senseful reasons, but the download must not strip essential functionality.
Why does the background image has to be uploaded while in the listing content the file can be linked?
The link functionality should be re-implemented for the background image.