EUC XL? Painting dress

Painting dress of unknown origin. Floral painting of ocre, brown, light blue, pale green, soft purple and red. Empire waist. I looks like clothing you can found in Art Museums’ giftshops. I received it as a gift and never wore it because it is too small for me. Pristine condition, but unsure if it was wore before I got it. Tag is for 3X, but measurements are more of XL. I’m a size 16-18 and it doesn’t fit me. Please see measurements below. No material tag, but feels like polyester. Fabric is not stretchy at all. Ptp approx. 23 inches Shoulder to shoulder approx. 17 inches Approx. 55 inches long Arm opening approx. 11 inches (22 inches total) Sleeve exit approx. 7.5 inches (15 inches total) Dog-friendly 🐕‍🦺, smoke-free 🚭 home