It is heaps easy to doctor a picture to look like anything you want! With the right programs, hell even with Photoshop you can make a skin into a sphere. With the right skills you can personally take a photo of an album cover, scan it into PS then using the right techniques make it 'look' like a ball. That picture has also obviously been touched up, colours and hew are wrong, saturation levels are too deep and whether you like it or smog pollution is usually visible over parts of the US and Asia.
I also believe that by editing the picture to make it look better (the asturation etc) is an easy way to hide any imperfections in making the previous doctor of making the picture spherical!