Girls Generation... comeback??? Misterious project for December 21th.

A misterious logo has apeared on SM Town Facebook page and Tweeter this Dec. 20th.

Nothing for sure so far. Could be a comeback or just a special song release.
Acording to rumors this could be the pre-release of GG 4th Album to be released in January in theory.
Some other said its just a special song, the remake of one of  old GG Korean songs.

Whatever its is the truth will come up on December 21th 10:00 am Korea time.