This image is in the public domain in Denmark because the DanishConsolidated Act on Copyright of 2010 specifies (§91, 5) that all photographic images not considered to be "photographic works" that were created before 1 January 1970 are exempt from protection (details).
Note that "photographic works", which must display artistic merit or originality, enter the public domain 70 years after the death of the photographer and that photographs that are not considered works but created 1 January 1970 or later become public domain 50 years after they were created. See Licensing for details.
Some countries have a lower threshold of originality and may therefore apply a longer protection term for this image, so it may not be usable in such countries.
To uploader: For this to be applicable, creation year must be known (or known to be at least before 1970)
This work is in the public domain in the United States because it meets three requirements:
it was first published outside the United States (and not published in the U.S. within 30 days),
it was first published before 1 March 1989 without copyright notice or before 1964 without copyright renewal or before the source country established copyright relations with the United States,
it was in the public domain in its home country (丹麥) on the URAA date (1 January 1996).