4 Things We Still Haven't Seen in This Season of Game of Thrones but Are About To

It's definitely the Boltons fighting (in addition to getting a peek at Ramsay's creepy smirk above, you can also see the House Bolton sigil — a flayed man — on their shields), and it appears they're going up against the Wildlings (oh hey, Tormund). Are there enough of them to overtake Ramsay's army? Is the mysterious letter Sansa writes in "The Broken Man" a request that Littlefinger gather his troops?