Hm, now that was odd. A Halloween episode was perfect timing, but a Christmas episode right before that, that's kinda odd.

What Fluttershy said in the end is roughly how I feel, too. I don't like to play any kind of prank on people that causes bad feelings and discomfort, unless it's to a trivial degree. Just like Fluttershy said: Seeing others in such a state, caused by me, that would make me feel very bad, regardless of prank or not. The feelings are the same. A certain sensitivity combined with empathy prevents enjoyment of that.
Of course they could have told her to just be afraid, to accept the experience; that it's just one night and the whole point, but why should Fluttershy condition herself like that? It would change who she is, and with good, accepting friends, she is in the lovely position of not needing to. She can overcome her fears when it is really required, when it's serious. That's good enough.
They also could have told her that her many worries of being attacked are unfounded and that there's nothing to really be scared of, but that would have defeated the whole purpose of Nightmare Night. ( No, I don't mean candy. )

Speaking of which... Pinkie's candy bag art made me laugh so hard! Like soul images.
The episode generally had a lot of fun little details.
As mentioned in my tweet https://twitter.com/Dowlphin/status/660491881525153796 I must say though, they should really cut back on the ... Wilhelm squeaks ^^, haha. Gets as annoying as the screams can become. Funnily, this was a Halloween episode and as far as I can tell there was actually no Wilhelm SCREAM in it. (Not saying there should have been.)

Apparently they know how to make colored contact lenses in Equestria. Or what other means could Fluttershy have used to change her eye color?

Here are two more spontaneous thoughts I had while watching:

http://dowlphin.tumblr.com/post/132474652747/nightmare-night-dlc

http://dowlphin.tumblr.com/post/132474660237/angel-punny-that-moment-was-so-rich-in-pun-how