Why doesn't the Gedo Mazo have tails? If the Gedo Mazo is the emptied body of the Ten-Tails, then why don't any of its forms look like that? 

I have a theory as to why it doesn't have tails, maybe because its chakra was split into the Tailed Beasts and hence it lost its tails. But it still doesn't explain why none of the forms look like that considering that the Gedo Mazo is the way the body looked when Hagoromo Ōtsutsuki, the Sage of the Six Paths, sealed its empty body inside the moon with Chibaku Tensei (Planetary Devastation).

Any ideas as to why this might be?
The Gedo Mazo is just a recipient.
The body of Ten Tails is on the moon, Rikudou sent his body there.

I think Madara and Obito plans to take the chakra of the Juubi in the Gedo Mazo, the recipient, and put it back into the real body of Ten tails.