Wherever it appears on the internet, this picture is invariably described as
Copa America 1921. Emilio Solari, captain of Argentina, greeting Bartolome Brizuela of Paraguay at the 1921 South American Championship of Nations.
However, Brizuela made his international debut in 1925 and did not appear at the South American Championship of Nations until 1926, whereas Solari's last appearance at the championships was in 1924.
My theory is that the Paraguay player pictured is in fact the legendary Manuel Fleitas Solich.