Once in a while, I get asked "Is the 'Cup Tossing' real at 1912 Pike Place Starbucks?" It is real. When a customer orders a beverage, the register barista marks up the cup (or sometimes the sleeve). The register barista who stands closest to the espresso machine has the job of tossing the cups. If you're listening, you'll hear the barista who is about to toss the cup call out a number. "4 Cups" or "1 Cup". This alerts the espresso bar barista that cups are coming. The espresso bar barista momentarily stops what he or she is doing and indicates if ready. And then the cups gets tossed to the barista who has to catch them. It's an efficient way to get the cups from the register area to the bar.
It all happens pretty fast. I'm sure it's possible for customers to order a drink, pick it up, and never notice the cup tossing episodes!
Here's a couple videos of this from this morning.