EXPLANATION TIME! How Rarity knows it? This is a part that I erase from the comic because it was too long. Rarity in her shops, saw tons of time stallions and mares wanting to buy clothes of the opposite gender but never bought them because they were afraid. That's how Rarity know about Purple and knows how to handle the situation.
Soo… Rarity is going to leave it exactly the same, since it's currently not a short mane like a stallion, it's a short mane like a girly girly female mare girl womanly motherly matronly princessly femininely pretty princess girly girl.
Seriously, how does she look more girly with a short mane?
Seriously, how does she look more girly with a short mane?
Must be just me.