That is my most favourite statue in Prague. You wouldn’t expect a statue in the sky, would you? The hanging man is supposed to be Sigmund Freud. However, he looks like any other bearded man, Lenin for instance.
Why does Lenin or Freud or any other bearded man hang above the street? Ask David Černý, the author. He’s the only one who (perhaps) knows.
(Taken a week or two ago on my smartphone, I feel sorry for the low quality)