The stock photos that come with your Chromecast are beautiful and all, but if you want to switch things up, you can customise it a bit more to your liking. All you need is the Google Home app.
Photo by @iannn.
As How-To Geek explains, it's as simple as connecting your Chromecast device to Google Home. This used to be the Chromecast app and it's free on Android and iOS. Once your device is connected to the app, you should see a "Manage your devices" options menu in the top right corner. Tap it, and you'll see an option to "Personalise device and more". Once you opt-in to that, you're taken to the Backdrop screen and you can play around with your options.
How-To Geek runs down a few apps you can connect with to personalise your Chromecast:
Google Photos: Allows you to select custom albums from your Google Photos collections and display them as part of the Backdrop. You can create new albums at photos.google.com -- just click the "Create" link at the very top and choose "Albums."
Facebook: Just like with Google Photos, you can allow Chromecast to access your Facebook pictures -- you can pick and choose between folders to display.
Play Newsstand: If you use Google's Newsstand app, this is a super cool feature. Basically, it will show news headlines from your personalised feed in Newsstand on your TV.
You can also choose "Curated News" and Google will update the background with news relevant to your interests. You can also customise the background on AndroidTV, though you won't have as many options available. For more detail and step-by-step screenshots, head to How-To Geek's post at the link below.