The new feature is available on all Android devices with Google Play Services version 23.44.14
Google Cast is currently one of the best protocols for streaming media content and is built into Android, Android TV/Google TV, and is also supported by a number of soundbars and speakers. However, its controls weren't integrated with Android as well as they should have been. Now the situation has changed.
Previously, Google Cast media controls appeared as a regular notification, just like in any other app. However, after the update, Google Cast controls appear in the media player widget on smartphones running Android 13 (or newer).
This means that the media player widget in the quick settings area will show what media is playing on a nearby Google Cast device, including the title, play/pause buttons, and so on.
The controls are also visible on the lock screen. Additionally, the widget will show which device is being used to play media. The user can even change the audio output.