Shoppers cannot touch the garment, so the words have to do it. The describer turns composition and fit terms into feel, stretch, opacity and fit in plain language.
Composition, weight and knit type become clear lines about softness, warmth, sheerness and creasing.
Relaxed, boxy, cropped and high-rise are explained as what the shopper will actually see when they wear it.
Will it guess opacity from the fabric?
No. It says when a property is unknown and asks you to check, because the same fiber can vary.
Does it write the whole listing?
It writes the fabric and fit sections. The Fashion Copywriter covers full descriptions.