Does the filling of the 'Light Down Vest' actually contain duck down or goose down?

The specifications stated in official materials for HYEIN SEO's Light Down Vest are its filling and outer shell composition. The filling of this garment is filled with 100% Polyester^[1]. Generally, 'down' refers to the chest down feathers of ducks or geese, but in the apparel industry, it is often used as a general term referring to the silhouette itself of a lightly quilted vest. Synthetic fiber filling is more resistant to moisture than natural feathers, making it easy to maintain warmth even when wet and simple to care for.

The outer fabric forming the body is a blended fabric of 50% Polyurethane and 50% Rayon^[2]. Generally, when the elasticity and coated feel of polyurethane are added to the flexible drape of rayon, a surface texture similar to smooth faux leather is formed.

hmmm, the expression 'down' functions more as a name referring to a lightly puffed silhouette rather than feather content. Rather than relying on the thermal performance of natural down, the composition focuses on layered styling that highlights the smooth texture and silhouette of the outer shell.