A seat offered without a public explanation can be a quiet act of respect.

Offering a seat can be done in two ways, and one of them makes the other person a spectacle. Announced loudly, with a reason attached, it tells the whole carriage something about them and requires gratitude in front of an audience. Done quietly, standing up as though you were getting off anyway, it gives the same thing and costs them nothing.

If you offer something to someone who might need it, do it without narration. Move first and let them take it or not. Skip the explanation, and let them keep the moment private.