It's been my experience that anyone who does this is trying to hide the fact that the finial is missing or a huge air bubble. In this case, it seems the finial is probably missing since in the description the seller only mentions 2 of the duck nephews and the third is the finial.
Also beware of blurry pictures. Chances are anyone selling something on ebay has a digital camera and its almost hard to take a bad picture with one. If the picture is blurry, there's most likely a reason for it.