Shirt Dress H&Msmall? small?

This A Line button-down shirt dress has such a unique pattern of flowers and birds. It is missing the size tag but fits like an xs. This looks amazing with leggings, tights, or sandals or boots...so versatile! Light enough to wear year round. Measurements: 15 inches shoulder to shoulder, 18 inches pit to pit, longest length is 35.5 inches (back), shortest length is 33 inches (front)