So the first big thing they did was throw all the class-specific prisms out and boil them down to two: Glamour Prisms and Glamour Dispellers.

Glamour prisms let you take the appearance of items which can be equipped by a class and past them on to other items (In WoW terms, Transmogrification.) There are some restrictions like you can't glamour male-specific gear on females or vice-versa, you can't glamour a higher-leveled item onto a lower leveled item, and you can't glamour class-specific gear onto other classes.

The Glamour Dresser is essentially a HUGE wardrobe where you can store items you want to use in glamours without them eating up all your inventory. It takes 1 glamour prism to store an item in the Dresser.

Glamour plates are essentially custom Presets for glamours that don't use any glamour prisms to apply, but they can only be used in the major cities (Limsa, Gridania, Ul'dah, etc.) and cannot be applied out in the field. You configure these at your Glamour Dresser using items you've stored in the dresser or the Armoire (Which really only holds some seasonal items, achievement specific items, and the ARR Artifact gear.)