We've seen a few little changes here and there with Android 5.1, from minor animation tweaks to new features and functions like HD voice, Device Protection, and lockscreen adjustments, and animations are the main focus here as they're a huge part of Android Lollipop and material design. It seems Google is slowly rolling out some more animation focused changes to Android although this time things are happening within the Play Store application on devices, and it seems this may be a server side functionality that is being turned on by Google although it's unclear if it will only appear for those who have devices running on Android 5.1.
As you can probably imagine when it comes to most touch interactions on Android Lollipop or applications with material design style interfaces, these new animations within the Play Store respond to your touch with delightful transitions you'd see from third party launchers when opening and closing apps. The animations in the Play Store appear just about anywhere no matter what it is users interact with, so basically touching any button leading to anything will cause a nice little zoom in/zoom out animation that is rather visually pleasing, giving the Play Store a little more vibrant life.
Unfortunately, there's no way for users to get these animations on their own and you'll simply have to wait for Google to enable things. Time will tell if they begin to roll out to all users running a current version of Android or if it will require you to be on 5.0 Lollipop forward. The good news is that thanks to the video below from Akshay Jain, you can see what everything looks like with your own eyes. This adds one more element to the overall cohesiveness that Google is trying to achieve with the new design guidelines for Android with material design, and in due time we could see animations like these in every single corner of the Android operating system. Things are already moving in that direction as is and animations already exist in much of the system UI. Has anyone noticed these animations pop up on their own device?