I was all hyped to jump in on the prof's side, but this has nothing to do with grammar or Starbucks jargon. It has to do with taking the order correctly, and likely with upselling the order ('do you want fries with that?').

If you don't want to be upsold, don't patronize corporate fast-food chains.

I hope she wasn't ordering coffee too. It sounds as if she had too much already.

Assume that the monkey's hands are tied to the handlebars and suddenly the video is easy to understand.

The 'motorcycle' is not motorized. The guy jerks the lead and the motorcycle goes. The monkey has learned to 'push start' and jump onto the cycle so that it hurts less when the guy jerks the lead. He has also learned that if he lets the cycle fall it will hurt, a lot. And he has learned to jump off and stop the cycle before the lead runs out, for the same reason.