Don’t get me wrong, Fluttershy really didn’t mind the pranks that much, since they were usually harmless. What got on her nerves was how often she did it and when she did it. There’s a right time for everything Harmony, and at the Grand Galloping Gala isn’t the time to be pranking the Earl of Saddleburg.
Note: In my verse, Fluttershy starts to wear her back mane ina ponytail, shortly after Harmony was born. You don’t need pink curls flying in your face when your four-month-old is making portals in the floor.