That's a brilliant product.
Assuming it's reliable and user friendly, that's the kind of product I'd give my parents (or even grand mother) so that they can easily video chat with the rest of the family.
To help her remember the commands I made a reference sheet with the most common phrases, but what mainly helped her was to think of talking to Alexa as if she was talking to a dog: Giving clear, loudly spoken commands.
Also, my theory is this story is coming out intentionally ahead of CES where Google will likely show a similar product to both this "Portal" thing and Amazon's Echo Show/Spot.
https://androidandme.com/2018/01/news/google-assistant-smart...