Specially for tablet which is serve as home screen dashboard.
When someone is in the house (identified as person present at home) and when the tablet camera device see someone, I would like that the Companion app is activating the screen for some minutes.
It as feature that would be interesting to have into that companion app 
hm… not sure if this is even possible, because that would require active hardware controll through the companion app - Which is something that needs to be enabled by the hardware vendor.
So, even if some devices would allow that - many others would probably not… And it COULD become an issue when you are running the companion app on your smartphone for example.
Also, it would require, that the camera on your Tablet is always on - even if the display itself is turned off… and that’s probably also something no hardware vendor would implement in such way.
The workaround that I found is to use the app full kiosk browser which have this feature and use the HA web page.