I noticed that it only pulses when I'm stood behind the car - I.e. within range of the parking sensors. Over the course of 5 minutes it slows down, like it's going to sleep. If you walk away, it stops completely, and only the alarm LED under the rear-view mirror flashes.
Try it - lock your car (press lock once), then walk behind the car; he'll know you're checking him out
Try it - lock your car (press lock once), then walk behind the car; he'll know you're checking him out