I am sharing my experience of Android Dev Preview 2 with you.
Google added new "Clear All" option : These new option will let you clear out all your recent app from recents screen. You will get a new graphic icon of recent apps with No recent items text. Here is the New screen screenshot I have taken to show you guys at below.
Google also added new folder view : They added cool new folder view you will see the all apps icons in round. I have shared the screenshot of new folder view to show you guys at below.
New Human Emojis : Google added new Human Emojis in Android N Dev Preview 2 update which look more real than old yellow blob Emojis. You can see the changes at blow I have shared both old and new Emojis.
Download Android N Dev Preview 2 From below link to get all above features on your Phone.
Android N Dev Preview 2