One mug, four files: our favicon.ico is a PNG, and two of the SVGs differ by a line that changes nothing

The site has one logo, a beer mug drawn in about fifteen SVG elements. It is stored four times. Two of the copies are the same drawing with two sibling elements swapped, one is the same drawing on a dark plate with the safe-zone arithmetic in a comment, and the fourth is a PNG with the wrong extension and a content type to match.