This tutorial taught developers how to add shareable holiday-themed filters and overlays to their React video chat app using Twilio's DataTrack API. The developer was provided with a pre-built video chat app as a starting point, which they modified to work with the DataTrack API. The tutorial covered key points such as configuring the backend and frontend, publishing and subscribing to DataTracks, sending messages over DataTracks, rendering filters for local participants, and receiving and displaying filter changes from remote participants. With these modifications, the video chat app now allows users to select and share video overlays among all participants in real-time.