To clarify, because the original article doesn't really mention this: the photos that were uploaded to Wikimedia Commons were taken by a photographer hired by t

To clarify, because the original article doesn't really mention this: the photos that were uploaded to Wikimedia Commons were taken by a photographer hired by the museum, not Commons users. The museum is claiming that they hold copyright over the photos because even though the original artwork is in the public domain, the photo taken of it has its own copyright, held by the museum's photographer (and thus the museum).