Two unrelated questions (Youtube & new Camera app)

1. If you use the new Google camera app on an HTC One M8 (either the GPE or regular edition), do you still have to move the camera upwards in order to take a Lens Blur picture? Or does it just the use secondary camera to create the depth map? Because I think it would be pretty awesome if the app is smart to use the secondary depth-sensing camera on phones where it is available .

2. On the changelog for the latest Youtube update, it says that you can now create "YouTube Mix automatic playlists for music videos". What does this mean in practice, and how do you activate this feature? I was excited when I read it, because I had visions of being able to seed my Chromecast with a music genre and just let it play play videos automatically during a party. But I can't find any button to activate this feature in the app.

AndroidPolice doesn't even mention changelog item in their overview of the updated Youtube app. Also, a Google search for "YouTube Mix automatic playlist" turns up a grand total of zero results. So yeah, it's pretty mysterious.