Luna feels neglected. Rising the moon during the night is an important task, and belonging to the royal family alone is noteworthy. Despite these things, she still feels as if her older sister, Celestia, still does not fully trust her. Many times before she has tried to catch her attention, but it was merely brushed off; at least, until Luna's attitude starts to take a turn once more.
The older of the two is far from oblivious, and upon getting Luna to spit out what has been bothering her, she gives her the chance to really test her own view on her level of responsibility.