I just beat the Windwaker again, and when you play through it the second time you wear the lobster shirt for the whole game. Except I noticed that at the very end, after you beat Ganondorf and float to the surface, I wasn't wearing the lobster shirt. I was wearing the green tunic and hat. I just thought it was weird.
Also, when you're in the bubble underwater as you float up, the bubble take the shape of the hat around your head.

Another thing that was weird was that you can't save it after you beat it the second time. I just was kind of hoping to see if there was anything different the third time. But... no third time...

Nerdy... but now I can't wait for Twilight Princess or Phantom Hourglass. YUM!!