@Background Pony Number 17  
So how is that any better? A character needs to develop, not regress. And the ponies in this movie regressed big time. Applejack is bland as bread, Rarity seriously needs to shut the heck up sometimes, Fluttershy has no semblance of her canon courage, Pinkie Pie acts without thinking, Rainbow Dash recklessly endangers those who are supposed to be her friends, and Twilight Sparkle reverts to this. These are the characters we were supposed to be rooting for? They’re not heroic; they just happen to have done heroic things in the past. If there was any doubt in my mind that they weren’t ready to take up the Elements of Harmony in the first place, it’s all gone with this pile of horseapples.
 
 
@Kaden Bayne Vanciel  
I could only wish the movie wasn’t canon. Then I wouldn’t have to see so many main characters get their personalities thrown through the wringer.

Well maybe Twilight, I’d be better off WITHOUT YOUR STUPID SHOW!
 
…I’m sorry, it’s just… fyay this movie, man…

@Kaden Bayne Vanciel  
Don’t bother, My Little Pony: The Movie is indeed canon with Freindship is Magic.
 
Season 8 spoilers:  
Hippogriffs appear in season 8.  
Episode 6, Surf and/or Turf, takes place on Mount Aris.  
In the same episode, Twilight says the last time she was at Mount Aris, it was a “ghost town”.  
Also in the same episode, both The Storm King and Queen Novo are mentioned by name.
 
Proven.

@Background Pony Number 17 Reversion? She must’ve ALWAYS had that. Also, I believe that the film could be a different canon from the series. Like, some elements, like Nightmare Moon’s existence, Tirek and Scorpan, the Crystal Empire, and other characters had never existed. I’ll try to think up more details.

@Background Pony Number 17  
So people change, or change their actions? Is there a difference?
 
Also in her defence her friends really did screw up a lot. It’s like sending a bunch of naive innocent young ponies on a military mission doesn’t go well.

@Kaden Bayne Vanciel  

 
It’s not a different side of herself. We’re seeing the real Twilight Sparkle here.
 
Despite being the “Princess of Friendship”, friendship doesn’t come naturally to Twilight Sparkle. She has to consciously work at it–that’s pretty much been the show premise since the very first episode. In this scene Twilight’s not going out of character; in fact, she’s reverting back to the character she originally was before meeting Pinkie and the rest of the Mane Six.

@mycarhasaMoustache  
I think the point of the whole scene is that Twilight is being irrational. Not without reason, perhaps, but the means do not justify the ends.

@MLPFan2012  
Yea but considering they are standing on a beach in the middle of nowhere with no plan and Tempest on their tail how is shouting at her going to help. All they did the entire time was screw things up and Twilight has 1 moment of bad judgement and it becomes ok to shout at her….

That flaring horn…
 
Murder.

Don’t yell at the baby!

Funny thing is, if this was fanfiction or even the comics, we’d just dismiss this as bashing.

@Kaden Bayne Vanciel  
I’d say the situation she/they were in. Miles from home, hell, from Equestria, with practically everything herself, her friends, and Equestria as a whole has worked for on the line. To say the pressure may have gone to her head is a bit of an understatement.
 
Of course, we as the audience knew both that friendship was the way to go (from both Twilight’s friends and the general ideals Equestria/My Little Pony push) and that everything was going to work out in the end, while she… well, didn’t. It doesn’t justify her lashing out at her friends (or attempting to steal the pearl), but I wouldn’t say it was out of character.
 
Not to mention that the past two times they tried the “friendship approach,” they were nearly sold and/or captured. Makes a little more sense that Twilight would try something as drastic or desperate as stealing the pearl when faced with the destruction of Equestria if making friends failed before. Even if it didn’t actually fail (and ended up saving their asses in the end), Twilight didn’t know this at the time; she had her reasons for acting the way she did.

@MLPFan2012 I know that. Just where DID Twilight get this different side of herself from? Shining Armor?

@Kaden Bayne Vanciel  
She still abused her friend’s trust by going behind their backs to try and steal the pearl though. That’s why they were all angry with her and walked off after she snapped at Pinkie(except for Spike who stayed to try and consul her), and why she broke down in tears afterwards.

@Vivace Her element was magic. That, unlike Generosity, Laughter, Loyalty, Kindness, and Honesty, had NOTHING to do with friendship.

Although the actions of Rarity, Rainbow Dash especially, and Pinkie Pie potentially/genuinely hindered the mission and/or stressed Twilight out to the point that she did what she did, revealing to us a side of her hardly ever before seen, each of the former 3 behaved in a way appropriate for her Element of Harmony. Twilight’s decision, on the other hand, was an affront to ALL the Elements, so that’s why her friends got pissed at her.

@Wcctnoam  
Well considering her friends did nothing but act like a ball and chain the entire movie, Slowed her down, Got in the way, Trusted a shady stranger and gave away their position, yea she was the only one under pressure considering she was literally the key to the storm king taking over.  
If she had been on her own she could have just flown all the way to the Hippogriffia and wouldn’t have gotten captured.  
Shouting at someone that has the fate of the world on their shoulders and is surrounded by idiots does not help.

@WingbeatPony
 
I wasn’t talking to you, not sure what gave you that impression.

@WingbeatPony  
In addition, I feel like this scene shows evidence of things being edited for brevity. A lot of the things that I “read between the lines” are thematically significant to the movie, and the scene with Twilight immediately after this helps reinforce that. It was necessary for Twilight to “fail friendship” before being captured so that she could reaffirm her beliefs after Tempest projects her own failings onto Twilight. The rest of Twi’s friends also seem to be condensed into Pinkie’s point of view, so at the end when they move off wordlessly, it feels more like they’re rejecting Twilight in solidarity for insulting Pinkie Pie, rather than taking it as an affront to all of them, which is what I think the writers meant for it to be originally.

@Wcctnoam  
I wasn’t claiming Twilight had the moral high ground - I very specifically said she was wrong.
 
I was simply trying to explore her headspace in that scene, because it struck me as being out of character the first time I watched it. So yeah, my comment contains a lot of the same leaps of logic and skewed perspective. I was relating the scene from Twilight’s point of view to show how she could’ve come to that conclusion, because the alternative is that she just up and decided to steal the pearl after doing more or less the right thing up to that point.

I wasn’t angry at twilight for this but that was pretty harsh and unexpected…

@Wcctnoam If the other three princesses found out about this…

@mycarhasaMoustache
 
Twilight is the only one under pressure? She’s just the only one that can’t handle it. You’re making the same mistake she did, thinking everything is on her and her alone, and even worse, thinking that gives her a pass for committing an incredibly “unhelpful and selfish” act, assholeish and unponylike, both towards the seaponies she deceived and tried to swindle, and her best friends that she mistrusted like everyone else.
 
This is someone who just acted completely uncharacteristically of themselves, and when that happens you’re goddamn right you shout at them. Getting upset is entirely justifiable, and making that individual come back to their senses is, not only the exact opposite of “unhelpful and selfish”, but also priority over whatever the fuck else is going on.
 
And that, is why Twilight has no moral high ground in this scene, and why no pony calling her out on her bullshit would be wrong to do it, regardless of who it could’ve been.

Tl;dr

@WingbeatPony Basically because Twilight inherited traits from Celestia that resulted in Twilight becoming “evil” like that and abandoning friendship like when Christovao Ferreira abandoned Christianity? How did Celestia get THOSE traits? What would Novo say about Celestia? I think I have an idea regarding all of this myself. But did Celestia create a successor Caesar of her? Did they turn Equestria into another Roman Empire? Was Equestria NOT supposed to be the center of friendship? Was it a place-taker of the Crystal Empire until it came back? Were Novo and Celestia REALLY childhood friends? Who agrees with my ideas that are in the link? Should all of these questions be part of a blog for a FiMFiction group? And how would a sequel to the 2017 film play out, as in, what would the plot summary be?