Cash Shop Specials: 1/22 - 1/28

learn to read, it says, duration: 90 days..

So does the royal face coupon. But the face itself is permanent.
The question is valid: are these transparent "items" like face/hair changes (or Carta's Pearl) and make a permanent change to the character, or like transparent equips that can be worn and removed and eventually expire.

The answer appears to be that they are equips. They're in the Equip section of the cash shop and they can be double clicked to toggle on and off. So yeah, they expire.