Originally Posted by sinus
maybe it was projected and painted on the wall?
Unlikely, as it contains noise and dirt from the original... plus you can see the widths of paper used (so it has been printed to wallpaper, I'd say). Also I doubt a handpainted version would look exactly like the original (and this one does).
They might have used a sharpened (and edited) version of Plamdi's image
(on which I've based my versions). The colors seem to match.