On the "How GIS Works" page, scroll down and you'll see the first working example of a new workflow app being developed by Product Marketing and Web Operations. It lets you interact with the map at a level not possible in most Story Maps, while stepping you through a workflow to show how real people actually use GIS.
On the "Showcase" page, we've embedded a Story Map highlighting GIS success stories around the world.
The "What is GIS?" site is discoverable on the front page of esri.com in the footer (first link in the "Understanding GIS" column at the far left). You can also point people to the site using the shortcut "www.esri.com/what-is-gis".