It seems like if you have all 12 copies you will get one large Team Surprise picture on the back cover:
Quite similar to that 12 single release Koda Kumi had.
Just realized it comes with a DVD too! So it's just one song and one PV? No couplings or instrumental?
Guess that explains the 1000 yen price. Not too bad for a CD+DVD even if it is only the one song.