When the Google Home Hub leaks first started, everyone was miffed by the absence of a front-facing camera for Duo calls. Later, with the device's official announcement, those leaks were proven to be true, and Google explained that it chose to skip the cam for privacy reasons (though we all know the decision was more likely a matter of competitive pricing.) However, what we didn't know was that the Home Hub would indeed support Duo calls, even without the camera.
Google actually confirmed that in a tweet a few weeks ago, but there's also a new support page today that explains how to set up Duo calls on your Home Hub and what you can do with it.
Hey Shane, you can make Duo calls, the person you're talking to will see your profile picture!
— Made by Google (@madebygoogle) October 9, 2018
The page isn't very clear. It seems like it's been copied from the Smart Display support documents with one minor addition. There's a note at the top that says, "The device being used to contact your Google Home Hub must have a camera in order for the video calling feature to work."
Based on this and the tweet above, it seems like the other person needs to have a camera and the call must be a video one, not an audio-only call. (Why Google chooses to limit Duo calls to video on Smart Displays is beyond me.) You should see them live on your display, but they will only hear you and see your profile photo.
You can also video call your Home Hub from your phone, and the same will be true there, technically. Whoever is at home and picks up will see you, while you'll just hear them and see your own photo (because it's linked to your Google account).
Google has reached out to let us know that the Home Hub supports "Duo audio calls, and there doesn't have to have a camera on the other end." We've reached back to check whether this would be coming to other Smart Displays too — and Google Homes possibly.
- Shane Milton