fleet thicket
As it sounds, transmog!
'Alternative' style option when entering inventory, like Ascension is (or have its own menu entirely, with its own keybind
Vanity inventory slots you can put items into to get their look, respective slots for armor such as Helmet, etc
Does not need to include weapons or offhands / primary & secondaries, it could, but mostly for armor first.
Does not include slots that provide no look to the character obviously, such as rings or neck