[Teuthida]

I'll try to clear it up.

GameCube version is the standard Zelda game...how it was originally put together.

Link is left handed. Most people are right handed. Rather than switch Link's model around (because I'm assuming it would cause too many problems with cut scene continuity and how he interacts with environment and enemies) to make him right handed for the gesture movements they reversed the entire game.

So there is no "mirror mode." Just that the GameCube and Wii versions will be mirrored versions of each other. Left is right and right is left.