You think the whole room is watching you. The whole room thinks the whole room is watching them.

Attention is scarcer than embarrassment assumes. Everyone in the room is busy managing their own appearance, running the same private audit, which leaves very little processing power for yours. The feeling of being observed is real; the observation mostly is not.

Test it by trying to recall what anyone else wore or said at the last gathering you attended. The blank is the point. Use it as permission to speak up, ask the question, or wear the thing, since the audience you are performing for is largely not looking.