The phones stacked in the middle of the table are the only way some families remember each other’s faces.

Attention has to be somewhere, and a phone is very good at being the somewhere. Nothing about that makes anyone weak. It means that being together in a room no longer guarantees that anyone is looking at anyone, and families can go years exchanging words without exchanging much else.

You do not need a rule about devices. You need one stretch where the default is different. Dinner, a car ride, the last twenty minutes of an evening. Put the phones somewhere else for that window and do not explain why at length. Faces are surprisingly interesting when they are the only thing on offer.