This Google Play Music concept redesign is full of color and according to the creator, is meant to mesh well with Google's vision for material design. While there are certainly some similar elements between this set of concept renders and the actual Google Play Music app, the designer has taken some liberties by changing up bits and pieces of the app UI. For example and as stated above, the design of the app shown here is much more colorful and changes with the color scheme of the album art for the song that's currently playing. This color picker feature is present in quite a few different apps with elements of material design so this in itself isn't exactly new, but it's not something you'll see in Google Play Music, save for on the persistent lock screen notification for the Android O developer preview.
Moving beyond the color, the designer envisions that the buttons for things like streaming to Chromecast, and enabling or disabling things like Shuffle and Repeat should be interchangeable and at the discretion of the user, meaning the user should be able to reorder them any way they wish. While this would certainly be a nice touch, none of the buttons in the screenshots below are currently visible in the real app, so for them to customizable they would first have to be present on the main player screen. Then again, Google has likely chosen to keep them off the screen to keep things minimal and make the most of the available screen space on mobile devices.
While it might be hard to catch at first glance, another visual element that's been added in these designs is a border around the album art which matches other color elements on screen. Since these are just concepts, it's not likely that users will ever see anything like this from Google should they choose to redesign the Play Music Android app UI in the future, but users may appreciate it if some parts of this design were to make into the actual app. Of course, that would all be based on preference as not all users will care for the design shown here. Either way, it provides an alternate look at what Play Music could look like if it were to incorporate the color picker element into UI of the player page.