Public domain works must be out of copyright in both the United States and in the source country of the work in order to be hosted on the Commons. If the work is not a U.S. work, the file must have an additional copyright tag indicating the copyright status in the source country.
PD-1923Public domain in the United States//commons.wikimedia.org/wiki/Template:J%C3%BCrgen_Ovens_-_Justice_(or_Prudence,_Justice,_and_Peace)_-_Google_Art_Project
The official position taken by the Wikimedia Foundation is that "faithful reproductions of two-dimensional public domain works of art are public domain". This photographic reproduction is therefore also considered to be in the public domain. In other jurisdictions, re-use of this content may be restricted; see Reuse of PD-Art photographs for details.