Carnival of Harlequin is one of Joan Miró's best-known works. Harlequin was a common theater character who was usually the victim of unrequited love and frequently played the guitar. In this painting he is a guitar, with the diamond-patterned shirt associated with the character, along with other traditional features like the mustache, beard, admiral's hat, and pipe. He looks sad, perhaps because of the hole in his stomach, and Miró did have financial constraints at the time—he remembered sharing radishes for dinner with a friend because it was all he had.
It is thought that the title of the Gallery's painting refers to Mardi Gras, the celebration that begins the fasting of Lent. Other than Harlequin, it seems very joyous, with all kinds of hybrid creatures playing, singing, dancing, and celebrating. Some of the forms are anthropomorphized objects—for example, the ladder has an ear and an eye. Miró explained some of the imagery in 1978: "In the canvas certain elements appear that will be repeated later in other works: the ladder, an element of flight and evasion, but also of elevation; animals, and above all, insects, which I have always found very interesting; the dark sphere that appears to the right is a representation of the globe, because in those days I was obsessed with one idea: 'I must conquer the world!;' the cat, who was always by my side as I painted. The black triangle that appears in the window represents the Eiffel Tower. I tried to deepen the magical side of things."