Board Thread:Speculation House/@comment-4830106-20140829021527/@comment-173.58.251.107-20140830004248

Okay, here's my theory about the needle: It's a secret portal to Pixieland, and Cinder is secretly the ruler of a race of evil pixies that plan on destroying Remnant when Cinder lets them in after sewing a portal to Beacon Academy. And thus the story will shift from trying to stop the White Fang when Team RWBY realizes that it's not about stopping one man and his rogue army of animal thugs, and it's about stopping a race of mystical pixies from destroying all life in the galaxy.

That or she's simply sewing, and the thing has no real plot significance whatsoever.