I love my Chromecast. I get to cast anything in my web browser to me TV, watch movies, rent them from the Play store, etc.. It also displays some beatiful images it finds from art galleries and other places. While these images are great, Chromecast is a Google product, which means you can customize it and make it your own.
You will need to use Google Photos to do this. If you;re not using Google for your photos, go to Google.com, click on the boxes in the upper right and choose Photos. It should walk you through using it. You’ll need to make a collections (this used to be called albums).
Go to the Chromecast app, from the hamburger menu tap on Devices, then tap on the sprocket in the upper right corner. From there, tap on Backdrop. As you see, you can add weather, turn on Personal Photos. Once you tap on Personal Photos, it brings you to a place that shows your photo collections in Google. Choose the collection you want. (tip: I make a collection called Chromcast and put any photos I want to see on my TV there).
Once this is done, you can turn off the Photos you don’t want to see, turn on the features you might want, etc…