The seating plan can reveal relationships that smiling photographs make look effortless.

Photographs show everybody together; the plan shows what had to be arranged for that to be possible. Who cannot sit near whom, which side gets the front, whose absence needs explaining: a great deal of family knowledge is stored in that quiet piece of paper. Ease at an event is usually manufactured in advance by somebody thinking carefully about history. What looks natural was engineered.

If you are arranging something, treat the difficult placements as real work rather than pettiness. If you are attending, assume somebody thought hard about the room, and thank whoever did the thinking.