This official Google mockup of Material Design on a music player looks very nice, but I don't see how this will work in the real world.
In the fictional land that many mockups live in, you see a lot of large, picture-based design like this. The problem with this design style in the real world is answering the question of "where the hell do you source these images from?" In the real world, no one has the 2560x1440 background art for millions of albums that this design depends on.
Google seems to want to actually do this for real, so where will the wallpapers come from? Will Google Play Music support attaching a wallpaper image for my uploaded music the same way it supports attaching album art? Will purchased Google Play songs come with a wallpaper now? Will this screenshot just never, ever really happen and Google will fall back to a blurred, blown up image or some stock background? This is from a material design session that encourages app developers to do this, where the heck are they supposed to get these images from?
This mockup looks incredible, but a big part of the reason it looks so good is because of how "hand made" and curated it is. I wonder what the vast majority of songs in this app would look like when it is made programmatically, instead of in Photoshop with pictures from a professional photographer. The result usually looks like ass, which is why you only see design like this in mockups, and not in shipping apps.