The shadow IS photoshopped. Any shadow cast by sunlight will appear the same size as the object. That shadow is much larger and thus a fake.

No, the shadow does not appear to be photoshopped. The shadow is being cast from the balloon from which the photographer is taking the photo, not from the balloon in the photo. You can tell because of the glory around the shadow's basket. (Search for "Specter of the Brocken" for details of this atmospheric effect)

Unfortunately, the shadow is photoshopped...