This photo is one of those I haven't been able to un-see. I suppose that makes it memorable and is memorable by itself one of the marks of a good photo?
I think that you might finally have been able to define "art" for me, seriously. I think that is what separates art from everything else, and having had some bad experiences with the local art scene, it's refreshing to think about it differently. As for the photo, I wonder if it's some kind of water collection/storage structure and that's why it's a slight conical shape.
Also, here's an oldie but goodie about T/S lenses, and a funny quote from it (emphasis mine):
"For those new to camera movements; my opinion is to never correct converging verticals into perfect parallels. It is the best way to make a building look as if it will fall on top of you and one of my long-time pet hates in architectural photography. I almost always leave a little convergence. After all, it is a normal visual phenomenon!"
Focusing the Tilt-Shift Lens