Tipping has become very common in coffee shops, restaurants, valets, and home delivery service. Many workers, including waiters and waitresses like the woman in the video, live off of their tips.
Therefore for them tipping is another source of petty income. It thus matters to them a lot. People often do not care and walk off only paying the bill. Not realizing that they could make a tiny difference in someone’s life. Thus this video is all about how this waitress gets the biggest tip ever.