Just a test to check whether GitHub supports displaying GIMP (XCF) image files, not only Photoshop (PSD).
File gimp.xcf is the unmodified, imported and saved file gimp.svg desktop logo from the official GIMP repository (GPLv3).
With imagemagick installed, a simple call can create a PNG image
convert gimp.xcf gimp.png
which then could be used for visual diffing.