Google News Showcase: How does the new digital showcase for media content work?

News Showcase consists of “story panels” that will be shown in Google News on Android and iOS, and later in Google Discover and Google Search. With these story panels, participating publishers will have the opportunity to summarize several of their articles in their readers’ newsfeed. Further components such as video, audio or extended daily summaries will follow soon. How does this work and what other features are planned?