Particularly weed and various hallucinogens.
Warning: Teaser includes random-fucking numbers, Illuminati symbols, the middle finger (a big fuck you to loyal fans!), nude sculptures, various glorified animals (encouraging bestiality, yum), and a million other things that you won't fully understand until you watch the teaser.
All this creepy symbolism and 'splendid' mixing makes this the perfect video to watch while high... Personally, I was laughing throughout the whole thing (full screen + full volume). On the other hand, it's definitely not something you could call "professional", and may influence younger fans to experiment with drugs (that's right, SNSD is PG-13 bitches!). SM executives, y'all need to learn to "handle your shit".
That said, the teaser will probably be 100x more entertaining than the actual music video itself (no offense girls).