P.S. "Album Artwork" and "Artist Picture" are native MB terms
Oh yeah, I totally understand the resistant on this idea, and I have no doubt that you have thought about this too.
Allow me to share how I reached my thoughts, just as something to consider (or not)...
As NP uses two output file types, a text file and picture, it makes sense to use these words ... "file" and "picture", but more strict than current use.
For example, the current "Artwork File" is type picture, so I thought, hmm "Artwork Picture". However, I then improved (in my mind) on this ... the word "Artwork" could be used for all pictures, and "Album" could be an incorrect term due to singles and podcasts, so I thought a more meaningful and descriptive word is "Cover" with type "Picture".
The word "Artist", does not always apply, for example soundtracks, factual audiobooks, radio programmes.
So, words that make sense with the above variations, and taking into account all that you clarified as the behaviours of each of these features..
Current Label Suggested Label Filename
"Text file:" "Tags file:" Tags.txt
"Artwork File:" "Cover picture:" CoverArtwork.jpg
"Primary artist picture:" "Backdrop picture:" PrimaryBackDrop.jpg
"Artist picture filenames file:" "Artwork backdrops file:" ArtworkBackDrops.txt
I think the labels in the middle are simpler than those on the left and describe to the user what the fields are actually used for. The other thought i had was to add "name" after picture but meh! The filenames on the above right column follow some logic too
I do feel MB should also look at picture/album/artist terminologies, but understand higher priority issues exist.