I googled it too. The video I found said it keeps the yarn from twisting in the back; I haven't done much with stranded knitting, just some practice, but twisting the yarn strands is something I've been working to do. Yeah, let us know how it works out for you.
Cheating is an option. . . . Cheaters never win and winners never cheat, but smart knitters who want to retain an iota of sanity do, cheerfully. ~~Kory Stamper