Two broad families
1. Change of mind (the collector's choice) The piece is fine, the collector simply changed their mind (where your policy allows returns). In this case the collector pays the return shipping, which is deducted from their refund. This doesn't reflect any fault on your side.
2. Something was wrong (fault-based) The piece arrived damaged, not as described, defective, or it was the wrong item. Here the collector never pays to return it, and the cost sits with the party at fault (the maker or the carrier). These cases can affect your payout for that piece (see Refunds & your payout).
What you'll see on the card
Reason — e.g. changed mind, damaged in transit, not as described, wrong item, defective.
Resolution — what the collector is getting: refund, store credit, exchange, repair, or keep the item (with a partial gesture).
The collector's photos / videos when they reported a problem — open them to judge the case.
Why this is fair to you
For change-of-mind returns, you're not penalised: the collector bears the return cost.
For fault-based returns, you can still contest within the window if you believe the claim is wrong (see Contesting a return), and you decide on the condition of the piece when it comes back.
Good to know
Some fault-based cases are resolved without a physical return — for example a minor issue where it's simpler for everyone to let the collector keep the piece with a partial refund or store credit. You'll still see these in After-sales.