This is a minor discrepancy when verifying web source script results before applying them.
In this example I used musicbrainz expanded and looked up this album.
I've tested it in Light and Dark mode so I don't think it's theme related.
On Windows, the linked result on the left is highlighted alongside the filename on the right.
Especially on multi-disc releases where there might be a few files or even discs out of order I find this visual indication very helpful to check if filename and result are in sync by clicking onto every 10ish filename on the right to see if the highlighted result on the left matches.
While I don't consider it to be an essential feature it would be very neat if there was a way to make it work in Wine as well.