Artist’s description.
 
 
In the Dancerverse, Flurry Heart is the Hero-Queen/Princess of Equestria. When her mother, Queen Cadence, turned to darkness, it was Flurry Heart who lead the battle against her, and eventually banished her with the power of the Crystal Heart. Though technically the Queen, she prefers the title of Princess in honour of her mother, who she still believed would return anyway. Some crazy little ponies believed that Flurry Heart intentionally usurped her mother, but those are all just rumours.
 
After becoming Queen, Flurry Heart took it upon herself to personally make sure that Equestria is never troubled by the evils of the worlds, defending her land against some particularly unfriendly neighbours. The reason why Moondancer was allowed to just hang out in Ponyville and fix small slice-of-life problems was because Flurry Heart was away warding off the greater evils of the world. She was, and is, essentially the Dancerverse’s superman, as in most of the battles she took part in, she won. To hammer it even further in, her cutiemark is a golden heart, representing her kind and good nature. Her lost to the Umbrum Queen Platinum was a shock and surprise to everyone who witnessed it, even the Umbrum herself.
 
On a subconscious level, Flurry Heart knows she’s overworking herself way too hard. It’s why she decides to make Moondancer her apprentice: so she could help carry the weight on her shoulders. The thing is, she doesn’t exactly like having other ponies help her when she believes they don’t need to. “Worry not citizen, I will take care of this!”
 
 
“Do Princess Dream of Magic Sheep?” Would be replaced with something like Flurry Heart working herself so hard that she slips and accidentally lets a dangerous evil loose. The Mane 6 insists on helping her, but she refuses, until the danger grows so powerful that even she can’t handle it alone, which is where Cadence steps in to lend her a hoof. Cadence is able to hold the danger back for a while, while also convincing Flurry Heart to tell everyone just why she wants to fix everything by herself. It basically comes down to Flurry Heart blaming herself for Cadence’s fall, and that she feels like fixing Equestria’s problems is her way of atoning. Cadence makes it clear that she has already forgiven her, in turn she asks if Flurry Heart forgives herself.
 
She also chose Moondancer because she had magic floating eyebrows like she does. :U