Video narration
You press the button for a snack. For a moment, nothing happens. Then the machine begins its sequence. First, it identifies the selected slot—the row you chose—and checks it. The button did not release the snack. It told the machine where to look and what to start. Now the spiral motor turns. The spiral pushes the snack forward until it passes the edge. Then gravity takes over, and the snack drops into the pickup area. But the machine does not assume the job is finished. A delivery sensor detects the snack arriving. That confirms the handoff. So the button is only the beginning: first a selected-slot check, then a spiral motor turning, then the fall, and finally a delivery sensor confirming delivery. What looks like one instant drop is really a chain from your choice to the snack in your hand.