Rewatch the teaser. Starting at 0:39 you see the following in the top right corner:
That is unmistakably the Face of Majora on this artifact. Slightly different shape than the Mask, but undeniably designed to be similar.
In the next two cuts, you see more evidence in the pedestal and other jewelry:
Finally, the last cut of the body, where the eyes glow, gives you (1) a better look at the necklace/earring/pendant, and (2) seems IMO very reminiscent of the Moon's eyes in Majora's Mask.
Could this body be Majora himself?
I was already hyped at just getting BotW 2 announced but now that I've realized it possibly directly parallels Majora's Mask, I'm hyped more than ever!
Edit: As I've been proven less knowledgeable about Zelda than some others here, it's been pointed out that the face seen here is the Crest of the Gerudo. This could still be connected to Majora - it's possible that he/she was a member of the Gerudo tribe, after all - but I'm currently more inclined to believe now that this may be the body of Ganondorf.