The Norah Jones “Covers” SACD (from the box set) has a cover that looks like a B&W picture of Johnny Cash.
Hi David,
That could be a stock pic indicating there’s no album cover available.
I looked at that album on allmusic and there was no cover artwork there either.
If you have the artwork or can find it, you can add it yourself.
You have some interesting albums. You’re really challenging Roon’s metadata service. 
Better metadata handling is coming in the next major release. No timeline though. Anyway, keep posting these issues.
Cheers, Greg