A photo of a sculpture is in no way a substitute for the sculpture.
The pixel art is in no way a substitute for the original photo, either.
Not at all. ALL architectural works constructed after 1990 are now copyrighted in the U.S., so any photography of any vaguely new buildings/structures is an infringement. (Sculptures have long been protected.) Give it another 50 years and it won't be possible to legally take a photograph outdoors in any location where humans have built anything.
Since I'm certain people will downvote or post snarky "CITATION???" comments without googling, here's your preemptive cite:
http://en.wikipedia.org/wiki/Copyright_in_architecture_in_th...
Total misunderstanding of how copyright in architecture works. If you build a new building, I can't copy your design and build an identical building across the street. But I can take all the photos I want of it. From _your own link_:
"First, when a building is ordinarily visible from a public place, its protection as an 'architectural work' does not include the right to prevent the making, distributing, or public display of pictures, photographs, or other pictorial representations of the work. The architect will not be able to prevent people from taking photographs or otherwise producing pictorial representations of the building."
And yes, it's utterly disgusting.
I don't know about the other examples, but the Rock Hall lost that battle:
http://www.gentilephoto.com/html/bio_frame.htm
As it happens, I live nearby, and I've used my big black camera and tripod on the premises many times without incident. The security guards have always been friendly to me.
I think the overall trend of wealthy organizations and individuals attempting to broaden their intellectual property holdings this way is a symptom of the way high litigation costs result in asymmetric access to the legal system. The Rock Hall (or Jay Maisel) can afford to litigate forever. I'd be utterly ruined by even a single lawsuit.
I've heard of lots of times where photographers were threatened by security, even police. I've also heard of many cases where they were able to show that the photography WAS legal, and were left alone. Just because police/security says something is illegal, it doesn't make it wrong. That's why we have courts, although unfortunately going to court can be risky and expensive, even when you're right.