It's an odd painting, but it really does create the illusion of movement. I've had a go myself using the children descending the staircase.
Difficult to create but strobe flash is a wonderfull thing!
Nude Descending a Staircase, No. 2, was painted by Duchamp in 1912. When it was first exhibited at the legendary Armory Show in New York (February 17-March 15, 1913), it caused an uproar which both outraged many people and made Duchamp famous in America. One critic called it "an explosion in a shingle factory."