13:10 Are we ever getting any explanation for those mouthpieces?

“The damane have these gold mouth stoppers; that’s not in the books,” she says. “But when I was doing my research, one of the things I came across in pre-Aztec research information was an actual image of a big gold stopper, and I thought that was really cool. And it also suggests that the damane have been silenced and they are the slaves.”

Your explanation is that one person that it was really cool. And some random words put together into a sentence that show the person understands nothing about Seanchan. Which fits into the overall theme that the Seanchan are not here to reconquer what was lost, but to battle the Dark. Which, in the books, they didn't believe in since their portal monsters had effectively destroyed all the forces of the dark on that continent.