When an Image Studio edit finishes, the notification names the edit that ran and the filename of the photo it produced, so two variations of the same shot are easy to tell apart. Your Credit Activity entry names the source photo instead, so you can always trace which original a credit was spent on.
Clicking the notification opens that exact photo's preview in your Media Library, the same view you get from the preview icon on its tile. When an edit produces more than one variation you get a notification for each, so you can open either directly.
Standard edits no longer show a 2K resolution suffix in the notification or in your credit history. Upscale notifications keep their resolution token because the output tier is the whole point of that operation.