I do apologize for the silly title, but one cannot always be brilliant…
This picture was sent from Sofia (Bulgaria) on May 22, 1919, by an Italian captain to his brother. All I know about this officer is his first name: Enrico. What did he do in Bulgaria in 1919? Simple: he was a member of the occupation troops.
Indeed, according to the Armistice Terms Agreed by Bulgaria and Allies (September 29, 1918), the military occupation of Bulgaria was entrusted to British, French, and Italian forces, and the evacuated portions of Greece and Serbia, respectively, to Greek and Serbian troops (Source: Source Records of the Great War, Vol. IV, ed. Charles F. Horne, National Alumni 1923). Italian troops replaced British ones in February 1919 and remained in this country until July 1919.