A Live Activity isn't a notification

You're in another app and there's a timer counting down at the top of your phone. You lock the screen and the same timer is sitting there. You swipe down to the Notification Center and it's there too, still ticking. It looks like a notification, but a notification can't tick. That's a Live Activity. It looks like three different surfaces (Dynamic Island, lock-screen banner, Notification Center entry), but they're the same widget, rendered three ways by the OS. I wired one up for Tomoe, a focus t