The Dancing Times archives are owned by the UK's Royal Academy of Dance, whose archivist confirmed via email, "there is no copyright for reproducing the actual cover of the magazine from that date, and the picture can be used," and furthermore, "there is no indication of who the photographer was, as they were not credited within the printed magazine." The complete cover is therefore assumed to be in the public domain.
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. Note: This tag should not be used for sound recordings.PD-1923Public domain in the United States//commons.wikimedia.org/wiki/File:Dancing_Times,_1927.jpg