In addition to showing the filename, you can add up to three labels to your thumbnail previews in contact sheets. Use the power of variables to display useful metadata, such as the byline for each photo in this example:

To change your thumbnail display, go to Photo Mechanic>Preferences>Contact Sheet.

Change the number of labels you want to display and add the text or variables for each label. 

Tip: You can also combine multiple variables and text, such as if you wanted to display any available GPS coordinate metadata:

GPS Lat: {latitude}, Lon: {longitude}