What detail does Auden include in his poem that is not part of story Icarus and Daedalus?

W.H. Auden includes the detail of Icarus' "wings' dancing shadow" in his poem "Musée des Beaux Arts". This detail is not part of the original myth of Icarus and Daedalus, which focuses on Icarus' hubris and his fall to his death after flying too close to the sun. Auden's inclusion of this detail adds a sense of beauty and tragedy to the poem, as it highlights the contrast between the grace and elegance of Icarus' wings and the inevitable disaster that awaits him.