It's too dark and missing details. Examine the image with Photoshop's Histogram panel.
I also think you might have IP problems with this. See circled areas in my screenshot.
Thanks! Black reflective background AU always rejects?
Definitely underexposed; try photographing it against a lighter colored background.
Thanks! But the object is specially shot against a black reflective background. Is it always bad for the AS?
I don't know whether Adobe Stock automatically rejects items shor against a black reflective background; it seems unlikely that they would do so. If you want to emphasize the details of this item and its reflections, you should experiment with different lighting scenarios and positions of the item that emphasize the edges more. It just sort of blends into the background here.
I don't mind the dark reflective surface it sits on. But I think the side arm needs more light to show details. It's in surprisingly good condition for it's 69 year age. Looks like someone took care of it.
This is my pistol 🙂