Audible lock screen controls

[MKREdit]

I use Audible to listen to books on my Galaxy Nexus and its great. The one thing I have not been able to figure out. The controls sometimes apear on the lock screen and some time they don't and I havent been able to figure out what determines there appearance any ideas?

 

[DanPLC]

Some apps only display lock screen controls when the audio is playing. Could that be what it's using? (Just guessing since I don't use that app).