We heard some times ago that Duo on Android would get the ability to video call your linked Smart displays. In typically Google fashion, the update was released out over a fairly long period of time, but it seems it’s now pretty much everywhere.
If you have an Assistant Smart Display you should now find a “Call my Home Devices” option in your Duo contacts on Android.
Simply tap the icon in the Duo app and all of your linked Smart Displays will start ringing! Depending on your device you can also use the Google Assistant command “Video Call ‘device name'”, to initiate a direct connection between your phone and a specific device.
This is a great way to keep in touch with those at home when you’re out and about, but remember that the video call might be one way only, unless the device on the other end actually has a video camera.
Unfortunately, this feature is very hit and miss, for instance it doesn’t work on my Pixel, but does on a Galaxy S10.