The video shows how the calculator app responds to a stylus with lighting effects on buttons touched by the stylus' virtual pointer. It offers a glimpse of the responsiveness to inputs in the Groove Music app, Print 3D, Outlook, and other apps.
The design changes aren't drastic and might not even be noticed by many users, but should have a wide impact as third-party developers adopt Microsoft's Fluent Design tools to present their apps in the same way.
Besides design tweaks, the Fall Creators Update will introduce a wide variety of new features, such as OneDrive Files on Demand, which is now built into Windows and doesn't copy the files locally. There are also several improvements to Edge, such as managing saved Favorites, and a shortcut to emojis. Cortana's settings are also now accessible within Settings, and the assistant displays answers in slide-out window from the Start menu.
As the Fall Creators Update rolls out, it should give more Windows 10 users the chance to try Microsoft's Continue on PC feature which is bundled in its new Edge apps for iOS and Android. The feature makes it easier to share a web site, app, photo, and other information from a phone to a Windows 10 PCs.
Microsoft had hoped to deliver the Timeline by the Fall Creators Update but has since deferred it, likely to the the Redstone 4 release. Timeline shows users activities they've done in the past, that they can navigate back to through cards.