How did Marcel Duchamp’s altered Mona Lisa photograph express Dadaist ideas?

Marcel Duchamp’s 1919 work L.H.O.O.Q., which featured a postcard reproduction of the Mona Lisa defaced with a mustache and goatee, served as a potent expression of Dadaist philosophy.21

By irreverently altering one of the most iconic paintings in history, Duchamp demonstrated the Dadaists' profound scorn for traditional art. This act was not merely a prank but a rejection of the artistic conventions and cultural values of a civilization that had produced the horrors of World War I.21

Through this "ready-made," Duchamp challenged the sanctity of established masterpieces, reflecting the movement's broader nihilistic and anti-aesthetic critique of society. His work effectively turned art into a form of criticism, asserting that the intellectual intent of the artist was more significant than the object itself.321