In the US buildings are covered under freedom of panorama and photographs of buildings taken from public areas are not copyright infringement. Sculptures are not covered under freedom of panorama in the US, and generally photographs of sculptures or other works of art are derivative works.
Second there is a major distinction between commercial use and fine art. Selling an image on a stock photo site to be used in an advertisement requires a release from any models, or from the sculptures copyright owner in this case. If they were selling a limited number of fine art prints they would not need a release.
Second there is a major distinction between commercial use and fine art. Selling an image on a stock photo site to be used in an advertisement requires a release from any models, or from the sculptures copyright owner in this case. If they were selling a limited number of fine art prints they would not need a release.