Why could this product be rejected?
vector graphic or pixel graphic?
I would guess pixel graphics as I see some artifacts, for example at the cut out line:
Perhaps these artifacts appeared when I used this program, thanks for not noticing them, they are not in the original.
vector graphic or pixel graphic? What format did you upload?
Rastor files such as JPEGs do not scale up well. If this is a vector then you should use SVG format.
I doubt the artifacts would happen when uploading to Adobe Stock.