1. In the Vault GUI, I right-click on $ and choose "Show Labels"
2. I right-click on the label in question and choose "Diff $"
3. In the dialog, for "Compare the label's contents to:" I select "Any local folder/file" and select the path to the files.
4. I click OK and I get an empty "Show Folder Differences" dialog:

I would expect to see a long list of files that are different, etc.
David