I recently heard the story of this image. It wasn't staged but a photo taken while Che was preparing to speak at a memorial service; he was listening intently to a speaker and the angle of the shot lends intensity to his expression. The man who took the photo was a Cuban photographer Alberto Korda. It's travelled around the world and become a symbol meaning different things to different people. It's not just pop-art! Korda refused to accept money for the photograph - he was Castro's personal photographer and a devoted Communist.
And Cal is currently somewhere above the Atlantic on his way to Cuba for a school trip so I thought that was a neat excuse to use the image.
The title comes from how Che signed off his last letter to Fidel.