Twilight isn't a tyrant. She is working to maintain both the cycle of the moon as well as the sun. This makes her naturally appear intimidating as she has such epic power. But she is only trying to maintain order within Equestria. And I can only assume that the ponies arrived to see advice of the Princess Who Never Sleeps on some type of urgent matter. And as you can see in the background, the rest of the Mane 6 passed away as shown by their mourning wreaths on the wall.



Does that help explain things?