I believe they are C4/Spotify instances. If I click on the Add Music button I see lots of options - Pandora, Sirius, Spotify Connect, Deezer, etc - so I'm assuming those are all C4 native services, right?
What is the expected behavior? If I use a C4 remote, go to listen, go into Spotify, and click a playlist, should it play even if my cell phone is turned off?