Rafe Judkins did a breakdown of the trailer,and he acknowledged that this is a deviation from the book Lan, but that they wanted to show that an Aes Sedai and Warder not only feel each other's physical pain, but emotional pain as well. Still not sure what causes such a dramatic outburst from Lan of all people, though.

We don't know that she's actually Aes Sedai, or if maybe they kidnapped her and took her to an abandoned shedding or something.
Either way, this isn't canon, but it's a good change for the show to make Whitecloaks more than a mere annoyance for Aes Sedai. Though hopefully they don't show the Whitecloaks being too successful. At that point, it becomes hard to believe the Aes Sedai let them survive and thrive for a thousand years.

This has as much chance of happening as Game of Thrones becoming the Ned Stark show, I think.