Whomever is working on the updates to the Appearances collection tab and adding things like the “Extra” tab and the set dropdowns, thank you so much, I really appreciate your work! I would say 50% of what keeps me in this game is farming old transmog gear/ getting new ones, and stuff like this is almost as exciting to me as a new expansion. Really appreciate your efforts, keep it up! 
I’m pretty sure that’s from Better transmog and wardrobe or something?
Oops! You are 100% right! It is an addon of some sort. Thanks for the correction! I thought blizzard was getting more transmog friendly 