This ain't exactly "mindblowing" but it's something that not a lot of people realize.
Link in Ocarina of Time and Link in Majora's Mask do
not use the same model:
Majora's Mask Link is much more detailed, he finally has a strap for his sword, his ears and hair are more detailed, his boots aren't as chunky, and he has detail on his tunic. For a game that's well-known for mostly reusing OoT assets, it's actually surprising that there's so many little differences that a lot of people don't notice since the models look so superficially similar.
It's like the anti-cloudbush.
Bonus: They actually bothered to make tiny differences to the Gorons between
OoT and
MM as well.