@Jfred01 Nice to see you around the Community.
Artist Only mode does exactly what it implies: plays only songs by the artist you used to seed your station (unless you've added variety to your station, in which case it will play tracks from those artists as well). This mode will only be available on some stations.
Listening in this mode should cycle through the various songs that artist has in our catalog vs. repeating an album over again. Of course if an artist doesn't have a lot of songs in our catalog, then there is a chance for a song or album to repeat.
Hope this helps clarify.