That's one of the things that's still being worked out. There are a number of possibilities that you can imagine. It could be a check mark. It could be a check mark accompanied by an audible sound. Think of a green light and a yellow light. The green light would mean it's authenticated. The yellow light would indicate that you should approach the call with care. Or a red light that says—
On March 10th, 2020. See this statement in context.