The Daydream app is getting an improved Home UI and improved controller performance as part of its latest update, which will put users on version 1.7 of the application. The update should be hitting devices as of today, but as is always the case, app updates don't generally hit every single device in the same day, which means some users may not see the update with these changes until sometime within the next few days. With that said, you can also bypass the wait and download the APK file for the Daydream VR app from the button below.
As for the actual changes to the UI itself, not much has changed visually, but Google does note that things are easier to see at a glance. The idea behind the slight redesign of the Daydream Home UI is to make it easier for users to discover new content that they may find intriguing and enjoy. Whether or not everyone feels that this is actually accomplished through the new UI will be dependent on people's personal opinions, but chances are content will be easier to find.
In addition to the redesigned Home UI the update will also be patching in improved performance of the Daydream controller. If you haven't noticed any performance issues with the controller up till now then you may not notice the improvements that Google has made once you update the app, but Google does state that performance and reliability have been improved. They've also added the ability to take a look at the Daydream controller in VR and see which buttons have been pressed. Google notes that button presses are highlighted only in a few places within the virtual space, and this includes Daydream Home, in the Play Store, or in the Quick Settings menu, meaning when you press a button in one of those locations you'll see the button highlighted visually. This might be minor, but it'll help to relay the fact that a button press response was registered, though it's also worth noting that to see the highlighted buttons after pressing one you'll need to look down slightly so you can see your virtual controller.