You likely typed a message but didn't hit send before exiting the app or switching to another conversation.
The identifier "83ED76EE-FBE5-47AD-B6EC-269D5C15355B.png" follows the naming convention for a locally stored image on an Apple device (typically from the Media/DCIM folder) or a file uploaded to a specific cloud session. 83ED76EE-FBE5-47AD-B6EC-269D5C15355B.png
Re-open the conversation, and your typed text should still be in the input field. Simply hit the Send button. You likely typed a message but didn't hit