... nobody knows.
There's two or three different kinds of cover artwork: The one available at Playstation.com, the one available at the PSN Store website, and the one available at the PSN store through the console itself (which apparently is used within the console too.) These are usually COMPLETELY DIFFERENT FROM EACH OTHER.
I tend to use the PSN Store website artwork, but others use the other artwork. What we are sure of is to never, ever use the retail box artwork (the full box scans) under any circumstances, because people will get confused and add the PSN versions to their collections by mistake.
Could you tell me what artwork you used?