I forgot you can also show the highlight field directly in the expanded panel of the Album Covers view.
Thats also implemented now
If I read this correctly, opening the expanded view of an album (in album cover view) should show highlighting. While I do see the single highlight on the album cover itself (in the -not- expanded view) I do not see any highlight next to the track in the expanded view.
In the fields displayed config, I changed album artist to highlight as a test. The highlight rule is "no lyrics" and the two tracks showing do not have lyrics. Nor do they show the highlight, which you can see on the album cover at the top.
Unless I'm misunderstand your comment, I'm assuming the highlight color would appear as it does on tracks view - a red rectangle next to the track name.