Attach invoices, collect vendor forms, request missing proof. Every one is ready to run, and you can adjust it in plain language.
Link the current proof file to its pending review item.
Your reviewers can open the proof from the approval item, with the filename beside the link when a draft is ready.
Show the current PDF proof and the question you need to answer.
Your reviewers get a clear task for the current proof. They know what decision to make and when it is due.