L.H.O.O.Q.

L.H.O.O.Q. () is a work of art by Marcel Duchamp. First conceived in 1919, the work is one of what Duchamp referred to as readymades, or more specifically a rectified ready-made. The readymade involves taking mundane, often utilitarian objects not generally considered to be art and transforming them, by adding to them, changing them, or (as in the case of his most famous work "Fountain") simply renaming and reorienting them and placing them in an appropriate setting. In "L.H.O.O.Q." the found object ("objet trouvé") is a cheap postcard reproduction of Leonardo da Vinci's early 16th-century painting "Mona Lisa" onto which Duchamp drew a moustache and beard in pencil and appended the title.
Overview.
The subject of the Mona Lisa treated satirically had already been explored in 1887 by (aka Sapeck) when he created "Mona Lisa smoking a pipe", published in "Le Rire". It is not clear, however, if Duchamp was familiar with Sapeck's work.
The name of the piece, "L.H.O.O.Q.", is a pun; the letters pronounced in French sound like "Elle a chaud au cul", "She is hot in the ", or "She has a hot ass"; "avoir chaud au cul" is a vulgar expression implying that a woman has sexual restlessness. In a late interview (Schwarz 203), Duchamp gives a loose translation of "L.H.O.O.Q." as "there is fire down below".
Francis Picabia, in an attempt to publish "L.H.O.O.Q." in his magazine "391" could not wait for the work to be sent from New York City, so with the permission of Duchamp, drew the moustache on Mona Lisa himself (forgetting the goatee). Picabia wrote underneath "Tableau Dada par Marcel Duchamp". Duchamp noticed the missing goatee. Two decades later, Duchamp corrected the omission on Picabia's replica, found by Jean Arp at a bookstore. Duchamp drew the goatee in black ink with a fountain pen, 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 on the iconic "Mona Lisa" and traditional art, a stroke of "épater le bourgeois" promoting the Dadaist ideals. According to one commentator:
The creation of "L.H.O.O.Q." profoundly transformed the perception of" La Joconde" (what the French call the painting, in contrast with the Americans and Germans, who call it the "Mona Lisa"). In 1919 the cult of "Jocondisme" was practically a secular religion of the French bourgeoisie and an important part of their self image as patrons of the arts. They regarded the painting with reverence, and Duchamp's salacious comment and defacement was a major stroke of "epater le bourgeois" ("freaking out" or substantially offending the bourgeois). 
According to Rhonda R. Shearer the apparent reproduction is in fact a copy partly modelled on Duchamp's own face.
Parodies of Duchamp's parodic "Mona Lisa".
Internet and computerized parodies.
The use of computers permitted new forms of parodies of "L.H.O.O.Q.", including interactive ones.
One form of computerized parody using the Internet juxtaposes layers over the original, on a webpage. In one example, the original layer is "Mona Lisa". The second layer is transparent in the main, but is opaque and obscures the original layer in some places (for example, where Duchamp located the moustache). This technology is described at the George Washington University Law School website. An example of this technology is a copy of "Mona Lisa" with a series of different superpositions—first Duchamp's moustache, then an eye patch, then a hat, a hamburger, and so on. This is a linkto the graphic. The point of this technology (which is explained on the foregoing website for a copyright law class) is that it permits making a parody that need not involve making an infringing copy of the original work if it simply uses an inline link to the original, which is presumably on an authorized webpage. According to the website at which the material is located:
The layers paradigm is significant in a computer-related or Internet context because it readily describes a system in which the person ultimately responsible for creating the composite (here, corresponding to [a modern-day] Duchamp) does not make a physical copy of the original work in the sense of storing it in permanent form (fixed as a copy) distributed to the end user. Rather, the person distributes only the material of the subsequent layers, [so that] the aggrieved copyright owner (here, corresponding to Leonardo da Vinci) distributes the material of the underlying [original "Mona Lisa"] layer, and the end user's system receives both. The end user's system then causes a temporary combination, in its computer RAM and the user's brain. The combination is a composite of the layers. Framing and superimposition of popup windows exemplify this paradigm. 
Other computer-implemented distortions of "L.H.O.O.Q." or "Mona Lisa" reproduce the elements of the original, thereby creating an infringing reproduction, if the underlying work is protected by copyright. (Leonardo's rights in "Mona Lisa" would, of course, have long expired had such rights existed in his age.) This is a link to examples of the foregoing parodies, together with an explanation of the technology. (These animations were originally prepared by the late Professor Ed Stephan of Western Washington University.)