In the last 2 episodes quite a few new characters were introduced but everyone submits those in various places.
I think the best place to submit Princess Cadance, Queen Chrysalis, BBBFF (Shining Armor) to Equestrian Royalty folder.
Changelings alone are Background characters and if it has Queen Chrysalis too then in Equestrian Royalty folder.
Group pictures of any combination of those also goes to Equestrian Royalty folder but if it has something unrelated in a group then goes Canon mixed.
I will update the folder information as soon as possible but for now whoever read this I would be very grateful if you submit to correct folder, it will save a lot of time for us and make approval faster.
p.s This does not apply to anthro/human, comics, animations and mature.