The pretty, pretty media player (mplayer front-end) continues to seduce me..but I got one issue I can't seem to resolve - how do I add cover art?

The app has a very iTunes-like album-scrolling-interface so I'd love to see some of my music that way.

There seems to be two ways to add cover art:
- scan for them on your device
(I do this but it finds nothing. I even placed the jpg in the folder for the album but it doesn't find it. Do I need to name it something in particular?)

- search online for cover art
(I do this and the search bar starts at 50% and then the app freezes).

How are you quasar users adding covers?