The friend who changes the seating has noticed something the conversation did not name.

Certain problems get solved by furniture rather than by discussion. Two people who cannot hear each other, someone stranded at the end of a table, a person who needs to leave early and is boxed in: naming any of that aloud would be awkward, and moving a chair fixes it without a word. That is attention, quietly applied. Noticing who is uncomfortable is a skill, and acting on it discreetly is a kindness.

At the next gathering, watch the edges of the group rather than the middle. If someone is stuck, make a small practical change instead of asking whether they are all right in front of everybody.