Famous buildings in the dirt

Today I was walking through Bristol, behind the Council House, when I looked up and saw a stain running down a bit of the wall that looked exactly like the building La Mole Antonelliana in Torino. I took a photo and later compared the two (got the other photo from Wiki). The similarities are remarkable. But, considering Bristol's fondness for graffiti, I can't be sure it's not a work of art. I am scratching my head over this. Either way, it's very pretty.