I mean conceptually, they look exactly the same. I'm not inattentive to small details. From a design standpoint, Twilight Princess is basically a heavily revised version of Ocarina of Time; no Link before that game had the effeminate eyes, and the brown gloves, or the white tights or blonde hair.
SqaS was faster than me pointing the differences, anyway. They are far from being just small details. The boots are not the same, the gauntlets are not the same, the hair is not the same, the robe is not the same, TP includes a coat of mail while OoT not. Dude, by changing the boots of the character you basically change around of the 20% of the character.
Look at this image:
Note that one of the Four Sword titles and A link between worlds is not present in the image.
Link will always be Link, but even there you can notice differences between all the different designs of Link and here is my classification:
1st Link = The Legend of Zelda - The Adventure of Link
2nd Link = A Link to the Past - Link
's awakening - Oracle of Ages - Oracle of Seasons - A Link Between Worlds
3rd Link = Ocarina of Time - Majora's Mask
4th Link = Four Swords - Wind Waker - Four Swords Adventure - Minish Cap - Phantom Hourglass - Spirit Tracks
Those are the type of Links that i know they are separated. However i dont know if there are 5 or 6 links:
5th Link: Twilight Princess - Skyward Sword (perhaps 6th Link rather than a variation of 5th, but those are EXTREMELY simmilar).