Monday Manners Rule #98: Never Insult the Way Someone Orders
What people drink, the way people drink, and how people order drinks will vary from city to city and from country to country to country. When a customer orders in a way that you may be unfamiliar with, or that you disapprove of, do not insult her. Just provide excellent service and the beverage that she ordered. You are there to do a job, and not to pass judgement on others.