Luna: The work is not very hard. You just have to check if any dragon, gryphon, timberwolf, changeling, any creature from the everfree forest come close to the castle and report it immediately, so if any of them appears to attack the castle under your watch, we'll know who to blame.
Guard: Okay. Wait! What? Luna: Hahahaha. Don't worry, they are other guards to help you if this happens. Guard: Uh... And does it happen frequently? Luna: Some nights are calmer than the other... It seems it is the case tonight for your first shift. Are you excited? Guard: A bit nervous... Luna: Don't be. Be more alert! Oh! One more thing." Guard: Yes? Your highness? Luna: You see that tower over there? Guard: The one where Princess Celestia's lives? Luna: Yes. That's the one. Guard: W-what about it? Luna: Don't ever try to watch by it's window. She will know you will. Guard: Huh? How? Luna: You'll see. Later that evening. Guard: I must not watch by her window... I must not watch by her window... But how could she know I'm watching... How?!? She is a princess after all.... Ahh! Must not watch... must not watch... He stopped at the closest place he know of the tower and took a peep. A pancart was there with written on it: "First night shift, uh? Go back to work, you voyeur!" He ran in the other direction. Meanwhile, in her room, Celestia was with Luna. Celestia: Hmph! You have to tell that to each of your new guard? Luna: What? I warned them to not look. It's their choice to do so. *grin*