Multi-user "Handoff" seems interesting as well. The implications from a lot of the descriptions is that this HomeView is designed from the perspective that every user also has a primary iPhone or iPad and HomeView coordinates data sync across a number of apps from that primary device. (Several features mention that they only work with that user's iPhone or iPad on the same Wifi network.)
the FAQ indicates this too:
> To unlock a full, personalized experience on HomeView, users need an Apple Account, a compatible iPhone or iPad, and to be added as a member of the shared home in the Home app.