No, it's a real piece. There's both Z and S pieces in real tetris. All possible shapes made with 4 conjoined blocks are in there.
FTW
I do not blieve the design of that piece is from an authorized edition of tetris, and may actually infringe on Nintendo's and/or Alexey Pajitnov's copyright/pantent/personal space or some such.
I was actually refering to the 'design' (the smiley faces, as opposed to the shape) its just the way I ammuse myself, I didnt actually mean it in seriousness