@Background Pony #DB57  
Even though she performed the Sonic Rainboom as filly back in The Cutiemark Chronicles? Yeah… I’m afraid the sentence “She’s built her entire performance around a feat that she never saw herself accomplish and which other ponies who were watching say she didn’t” is bullshit (also considering the mane six saw the Sonic Rainboom actually happen (and is what caused the events of getting their cutie marks to happen)).

SHE IS JUST TOO CUTE

@FlonnesIkramant  
Fluttershy: “She’s practiced [the Sonic Rainboom] a hundred times and she’s never even come close to doing it.”  
She’s built her entire performance around a feat that she never saw herself accomplish and which other ponies who were watching say she didn’t, which almost any sane pony would believe she couldn’t possibly have done, and is fully expecting, with strong evidence, to dramatically fail in front of a full stadium of sports spectators, Princess Celestia, and her lifelong idols, who she planned on getting her foot in the door to her lifelong dream by impressing.
 
Rainbow Dash has never been shown to be good at hiding her emotions at other times, and she’s just been slapped with a brick wall of anxiety.

@martianmister  

@Crayv
 
I wouldn’t call her insecure.

@Crayv  
This would open a whole new world of character development.

“She actually didn’t see herself as the best flyer in Equestria.” Well yeah, Dash is rather insecure and uses bragging/showing off to hide it. Wish they would have gone more into this in the show, it seems like the writers kinda forgot that part of her.

Well, how would she know? It’s not like she had a lot of flying contests with flyers all over the world.