L.H.O.O.Q. and wrote "Moustache par Picabia / barbiche par Marcel Duchamp / avril 1942". As was the case with a number of his readymades, Duchamp made multiple versions of "L.H.O.O.Q." of differing sizes and in different media throughout his career, one of which, an unmodified black and white reproduction of the "Mona Lisa" mounted on card, is called "L.H.O.O.Q. Shaved". The masculinized female introduces the theme of gender reversal, which was popular with Duchamp, who adopted his own female pseudonym, Rrose Sélavy, pronounced "Eros, c'est la vie" ("Eros, that's life"). Primary responses to "L.H.O.O.Q." interpreted its meaning as being an attack
Marcel Duchamp included his first "machine" painting, "Coffee Mill (Moulin à café)" (1911), which he gave to his brother Raymond Duchamp-Villon. The later more figurative machine painting of 1914, "Chocolate Grinder" ("Broyeuse de chocolat"), prefigures the mechanism incorporated into the "Large Glass" on which he began work in New York the following year. Duchamp's first work to provoke significant controversy was "Nude Descending a Staircase, No. 2" "(Nu descendant un escalier n° 2)" (1912). The painting depicts the mechanistic motion of a nude, with superimposed facets, similar to motion pictures. It shows elements of both the fragmentation and synthesis of the Cubists,