The sharing menu is cleaner, with contact pictures replacing the generic box used to handle this function. Google says the update was coming to the Play Store. The latest edition is also hosted at APK Mirror. It didn’t include the sharing interface when I downloaded the file. So you may have to wait for the feature to appear in the official Play Store build.
The impact on you: If Drive is your go-to productivity suite, these are helpful changes. They’ll mainly be useful on large-screen phones. Like the Galaxy Note 4 or Android tablets, you can use all that space for collaboration working with various file types. Google also needs to keep pace with Drive on Android now that Office for Android phones brings new competition.