In short: Amongst the many hardware announcements today, Google also announced an update to the Google Home app. This update is a visual redesign to the app that will make it much easier to control the smart home devices that are in your home. Making it easier to just tap on a light and then adjust the brightness, or even turn it off if you wish to do so. You can also control a group of lights here, instead of just a single light. You also have the ability of controlling other smart home devices, through the app, without needing to use your voice. But when you do want to use your voice, you can access the Google Assistant from within the app, without needing to talk to your Google Home smart speaker.
Background: Google desperately needed to redesign the Google Home app, as it was quickly becoming a place where you can only connect your smart home devices to Google Assistant, and that was about it. If you wanted to control your lights without using your voice, you'd need to go into another app, or type to the Google Assistant. But now, you can control them like you are in the Philips Hue or LIFX app, which is a much needed change.
Impact: With these changes to Google Home, everyone can control the products in your home with the Google Home app, as long as they are under your roof, they can adjust the lights. Now this means that kids could definitely pull pranks on parents by turning off the lights or the TV, hopefully Google will add in some parental controls in the future. Now, Google has also added the ability to control multiple homes through the app. So if you need to help your parents turn off the lights, you can do it from your home without having to leave and do it yourself.
The Google Home app is rolling out to iOS and Android users later this week in a new update from the Apple App Store and Google Play Store respectively. This is going to be a staged rollout as usual, so it may take a few days before it reaches your device.