>>724985781
Given the way Zelda acts around it, I'm guessing that it's some sort of machine that's able to embody Zelda's memories of Link. Sort of like a mimic, but instead of mimicking the person, it mimic's whatever the person touching is thinking about at the time.

>>724104770
He might not be BoTW/ToTK Link, but I'd be shocked if he isn't a form of Link. The way Zelda reaches for him here, then hesitates, would be odd if he really is just a rando.