Some of the trophies were probably even ported from previously made games.
So that won't be that difficult for them to do trophies. Just look at Bridge of Eldin and Delfino Plaza.
Good point, but I don't think anyone's gonna disagree with me about the fact that trophies are more important than these stickers. They may not be hard to make either, but I'm pretty sure that 3D images are harder to make (or port) than 2D images, so my thoery still stands.
BTW, I'm not sure if Bridge of Eldin or Delfino Plaza are ported. They may just be remodeled. Possibly Delfino Plaza, but I think the backgroud for Bridge of Eldin may be different. I don't know, and I'm too lazy to boot up Twilight Princess to check especially since my Gamecube sucks more than Paris Hilton right now (I really need to get a Wii. My Gamecube is just..broken. It pisses me off so much.)