Each file uploaded will appear under the attachments column in your message correspondence. Both agents have the ability to change the file name displayed by clicking on the pencil icon next to each file. 

This is helpful if the same document like a purchase agreement is sent back and forth a few times for price counters. If the document name is never changed you may have multiple messages with an attachment called purchase agreement. Renaming the file name in MLS offers may help both agents better identify each version of the same doc.