I really love the bit, because this is what Celestia has been doing with Twilight for the entire series, and now Twilight is doing it to Fluttershy.
 
Twilight knows Fluttershy’s potential better than Fluttershy does. Twi knows that Flutters will be happier and more fulfilled if she tries to help Rainbow Dash and learns to connect with animals.
 
Twilight actually could have saved Rainbow Dash very easily with her telekinesis and whatnot. But that isn’t the point, that was never the point. The point was to let Fluttershy learn something important about who she really was - to help Fluttershy realize a potential she didn’t even know she had.
 
That is why Celestia had Twilight go do things so many times.
 

 
Addendum: It’s not technically cannibalism, since none of the animals are ponies, but it very much has the spirit of it; mob-like group tying someone up in a cauldron while wielding silverware like weapons :p