This is Link. He wields the Master Sword and he bows down to a figure, who might be Princess Zelda or some other incarnation of the Goddess Hylia. We don't know, who the woman is, but Nintendo certainly wants us to speculate over the contents of the new trailer.
There's also another faceless shot of a woman in the trailer, who's wearing a blue garb very similar to Link's:
She has blonde hair, she has an Adventure Pouch on her belt and it seems like she's holding the Sheikah Slate in her hands, but that's not sure. This is all essentially screaming "female Link", but it also might be that this is simply Zelda in a time, before Link woke up. Or she might even possess her own Sheikah Slate. In any case this looks a lot like a female character, who's potentially playable in some form. Why else would you put her in full adventure gear?
It could be that the blue-white-gold tunic is essentially something of a faction related to the Sheikah and/or the Goddess Hylia. It wouldn't be the first time that Nintendo uses Link's tunic for a group of people, e.g. the Kokiri, the Hyrule Castle Guards in Spirit Tracks or the Knights of Skyloft. But it doesn't necessarily explain the gloves or the Adventure Pouch. This female character is dressed for action.
There's also the bird guy, who is geared up to play hero:
Let's call him "Bird Link" for now. He's also wearing the same color scheme, though the blue tone is mostly in his scarf, but it seems like there are multiple characters in the game, who drive to be the Legendary Hero or at least fight for the good side in some form.
It's noticeable, how they are all dressed in a blue-white-gold color scheme, where the main color is blue and the game has the classic "Blue vs. Red" video game symbolic going on (which even was adapted by Hyrule Warriors). It's mostly reflected in the Sheikah technology, where blue represents a friendly state, red/pink/purple represents a corrupted/evil state and orange stands for a neutral state (like the Shrines that you haven't completed yet).
And the good guys are essentially all wearing the Sheikah Blue (trademarked color) to show off their disposition, all fighting for the Goddess Hylia. Blue isn't actually her color, but Nayru's, where Hylia usually was represented with either gold or a bright light, which might be where the white and gold color parts in all these outfits come in.
It will be interesting to see, how all of this will add up. But the most important question is right now, whether there are any playable characters next to the Link that we know and have seen so far. May it really be a "Linkle" as a gender choice or a playable Zelda, where you either get to play as her in some sort of 2nd Quest or special sequences in the game (maybe even flashbacks). It might also be that you get to play as the Bird Link at some point.
There's quite some potential here and hopefully Nintendo doesn't just do all this teasing without any bigger significance behind it.