I don't think that's it. While tattoo or piercing makes perfect sense, I doubt it's something you could call a major choice from a player's perspective. It would be something major for a dev, not for us.A major choice that would change parts of the story dramatically, and would influence almost every other scene? One that over 95% of the players won't choose? I have no idea what that could possibly be, but it sounds like a bad idea. Any guesses as to what they could be talking about?
A new tattoo in a very visible area? Something like that would affect almost all scenes, because you'd need to have an alternate render of every shot with him in it. But that wouldn't change the story drastically, unless it was an exceptionally awful tattoo.
A chance to start an exclusive relationship with Tori as her new boyfriend? That would change the story dramatically, and could possibly rule out more than 95% of people. Hell, it would probably just be me and a handful of others interested in that. So... yeah that one's worth it because I'd enjoy it, and I'm sure everyone else here would be totally cool with waiting twice as long to progress with their favourites. Right? You guys wouldn't mind that would you?
Tori route is probably also not it. The reason why I think that is because NYX wouldn't bother creating every scene twice just to show the reflection of your decision. I reckon she would just make Layla and Elena stop talking to you and that would be a perfect excuse to skip school scenes all together while showing the short Tori exclusive content