This is a faithful photographic reproduction of a two-dimensional, public domain work of art. The work of art itself is in the public domain for the following reason:
The author died in 1926, so this work is in the public domain in its country of origin and other countries and areas where the copyright term is the author's life plus 80 years or less.
You must also include a United States public domain tag to indicate why this work is in the public domain in the United States. Note that a few countries have copyright terms longer than 80 years: Mexico has 100 years, Jamaica has 95 years. This image may not be in the public domain in these countries, which moreover do not implement the rule of the shorter term. Côte d'Ivoire has a general copyright term of 99 years, but it does implement the rule of the shorter term.
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 the United States. In other jurisdictions, re-use of this content may be restricted; see Reuse of PD-Art photographs for details.