They used it in a sarcastic way: the first person in the world to be to the moon (as they advertise) weared the watch advertised and I think it's the OMEGA's watch. That's why you will be dressed well if you go to moon equipped with this watch.
My guess: The full moon is famous for partying, bacchanals, witches meetings etc etc... It's a big occasion, so you'd better be up to the standards, look your best, because it only happens once in a month. SO, our watch will make all the difference!