Not all album art are shown playing mp3

Musisc is played over the network.

All my MP3 have album arts. WDTV Live only shows some of them, how can I make it to show all album arts?

"All my MP3 have album arts. "

… I used to think that, too.   I use iTunes to manage my library, and I thought all the MP3s had Cover art, but it turns out that when you add cover art in iTunes, it doesn’t put that art into the MP3’s ID3 tag, it just stores it in a database.

You can examine your MP3s with a shareware tool called MP3TAG (here:  http://www.mp3tag.de/en/) and see if the cover art is actually there.

When I added the cover art using THAT tool, the WDTV saw them perfectly.

HOWEVER, I wish the WDTV would go more than one folder deep to look for thumbnails, but it doesn’t.   If your library has multiple levels of folders, you’ll see that too, in which case you can add a “folder.jpg” file and that will work.