I don't believe mp3tag does this so correct me if I am wrong.
It is possible to add albumart to a file by specifying a link to a cover.jpg in the same folder rather than including the image itself in the tag. Is it possible for mp3tag to show that information, and even display the image?
I have used media monkey together with batch art finder to generate the tags for my library, but would like to use mp3tag to check, as the tool is a little iffy.