Google Home Hub is the latest member of Google's popular smart speaker family. At first glance, it looks like a Google Home with an LCD bolted on top - which seems pretty superfluous, given you can use existng Homes to stream video to TVs.
However, it turns out that the main selling point isn't video streaming at all. (The key is in the product's name.) In short, it will act as the central hub for all your smart home devices, allowing you to control them at a glance.