And then, there were, of course, those people who flat out don't believe the buttons were made for labeling drinks or resetting another button. "It's for reducing spillage risks.

While many McDonald’s diners already knew what the circular nubs are for, many were shocked to learn the purpose of the rectangular ones. AP Photo/Matt Rourke Many people responded to the video ...

Essentially, the rectangular buttons serve as a sort of reset. If a McDonald's worker were to accidentally press the wrong circular button and label the wrong beverage, they can correct their ...