Currently, these Entries display just the title. Has anyone found a way to display entries as a thumbnail (from it's image field)? I'm starting to look at plugins, but haven't seen anything that would help yet.
This is not possible natively, and as far as I know there's currently no plugin to get a such display. You could develop you own plugin with a new custom field type.
However, if you double-click on this Entry you are able to view its fields within the small pop-up window. Maybe that could help if you need a quick preview of its image field.
You could also rethink the way you add your Work Entries: maybe this could be an Assets field instead of an Entries field. Like this, you would be able to display the thumbnail.