

In the past the solution was to use a Flickr album or choose from your Facebook albums and have photos display that way, but Google recently removed those experimental features. Which does actually work! But it’s super clunky.

Others have gotten more clever and found that you can simply favorite a bunch of photos and then select “Favorites” from the list of options to display them. Recently I’ve seen tons of articles showing how you can use “Recent Highlights” from your Google photos to let Google automatically choose from your most recently uploaded Google photos, but that’s a terrible solution in practice. Google appears to have quietly added a new feature to Chromecast ambient mode that allows you some mechanism to manually chose custom photos that show up there.
