As you will see in the JLC video here: www.youtube.com
k
The timer area (with numbers) is tight to the inner ring with the triangle. The red JL logo is on the hour hand and therefore moves with the hour hand to indicate the remaining time to the alarm.
Very clever, but not a specific mechanism. You'll also notice that the calibre is the same as the one of the Master Control Memovox (without the timer function).