A useful filename should identify the project and version without requiring you to open the image. Consistency matters more than an elaborate naming system.
Choose a few stable fields
Use a short project name, video identifier when available, version number, and status. For example, a pattern such as project-videoid-v03-approved separates identity from revision. Avoid names that expose private client details in public downloads.
Keep labels meaningful
Use approved only for the file actually selected. Do not call several different exports final, final-new, and final-real. Put dimensions in the filename when you maintain multiple sizes that would otherwise be confused.
Update the project record
When the chosen version changes, mark the new file clearly and archive the previous one. Keep the editable source under a related name. Test the naming system by asking whether another editor could find the current thumbnail without a verbal explanation or a search through message history.