Because that is not Canadian Metal four piece Tomb Mold. (They're pretty dorky looking too, it turns out, but that ain't them.)
I think I know why it's doing this: because my music library is organized under directories for each letter of the alphabet (/albums/T/Tomb Mold/...)
The same picture of eight Asian guys shows up for Talking Heads, too, for example. I'm just wondering if there's a way to specify a better placeholder image. I'm perfectly happy to go digging in the server's directories if that's what it takes.
When I Edit Images for the band, the Logo, Primary, and Backdrop images are all appropriate, so it's not using one of those (you'd think it would be Backdrop...) so I guess I'm digging for fanart.jpg.