Naim app , no artist pictures ?

[timster]

Not quite true. Its both server and control point. Lumin is different because it builds its own index.
Kazoo displays last.fm info once an artist container is opened, it doesn't itself show an artist picture in the artists list. I'm not sure what Lumin does when building its index, but if it's like Asset it would take a picture from an album for the artist and use that in the artists list. That may be what the OP is referring to.