https://www.youtube.com/watch?v=nEIFGmTIlRo&t=65s
If you zoom in on the blank area just above the goose neck, you will see an area of fabric pattern. This is NOT a jpg artifact.
If you adjust brightness and contrast, it will become even more clear.
I you use GIMP and auto adjust color levels suddenly it looses the overall red color.
Yes there is a zig-zag pattern.