Outerwear is bought on bulk and length. Both are volumetric, and a garment laid flat or hung on a hanger has had exactly that dimension pressed out of it. A shopper looking at a wool coat on a white background is guessing at the one property they care most about.
What the try-on shows
Your coat with the shopper inside it: how far it stands off the body, where the hem falls against their frame, how the collar sits at their shoulders. A padded jacket and a tailored one can look nearly identical hung up and look nothing alike worn.
Layering is the interesting part
Outerwear is worn over something, which makes it the natural case for a multi-garment try-on. Up to six garments compose in one generation — a coat over a knit over a shirt — for one credit rather than six. Order matters and the order you send is the order that gets layered.
This is worth building into the product page rather than leaving to the shopper. A "try with the roll-neck" alongside the coat is a better question than an empty upload box.
What to expect from it
Hardware and surface texture are the weak points. Zip pulls, buckles, a specific quilting pattern, the exact nap of a wool: expect the shape to be right and the fine detail to be approximate. Colour is generally reliable, but a very dark garment against a dark background gives the model less to separate.
It says nothing about warmth, weight or waterproofing. Those belong in your copy. Try-on answers "does this look right on me", and outerwear is a category where that question is usually about proportion.