“No! I… GAH!”

@Background Pony #FFDD  
One is also a dream.

@Background Pony #FFDD  
Good eye.

I feel pretty autistic to notice this and I don’t know if this was done on purpose, but you could tell that NMM is stil very much Luna from the inside here…  
!img4.wikia.nocookie.net/__cb20130104014140/mlp/images/thumb/e/ed/Nightmare_Moon_addresses_the_crowd_S1E01.png/640px-Nightmare_Moon_addresses_the_crowd_S1E01.png!!img1.wikia.nocookie.net/__cb20131125194046/mlp/images/thumb/a/ac/Nightmare_Moon_taunting_Princess_Celestia_S4E2.png/640px-Nightmare_Moon_taunting_Princess_Celestia_S4E2.png!  
Compare these two images with the one above of the most recent episode. The real NMM’s mane is more smokey style, while here it’s closer too Luna’s mane with the thick lines on the outside of her mane.

@Phantom Rider  
Don’t ruin it for me.

@someguy111  
Well, this is Luna in a dream she constructed for herself, not an actual moment from her villain days.

That expression she has implies she’s not as evil and menacing as she seems. She seems to have another side to her; a remorseful, possibly regretful and insightful side rather than just being crazy and evil.

“I’m not cute! I’m Terrifying!”

“Where are you going? You didn’t even call ‘safeword’!”