Professional etiquette is where cultural differences carry real career consequences, because the workplace judges constantly and explains rarely. The major variables: hierarchy, whether juniors challenge seniors openly or never in public; communication, blunt directness as honesty versus softened indirectness as respect; time, hard punctuality and fixed deadlines versus elastic scheduling; formality in titles, dress, and email tone; and relationship-building, cultures where trust must precede business versus those where business builds the trust. Industries layer on top, since a startup and a bank in the same city can run on different codes entirely.
Relationships form or fail on these details. A manager from a direct culture reads an indirect employee as evasive; the employee reads the manager as harsh. Meetings misfire when half the room thinks decisions happen there and half knows they happened beforehand in private conversations.