Future!Twilight’s tail is four times longer, very likely thicker, and therefore exponentially greater in both volume and mass. Most hair stylists will agree that greater mass requires more energy to move. Therefore, wagging it like the HNNG-inducing filly above probably requires conscious effort on Future!Twilight’s part, and if she’s out of practice, she’s likely to pull a muscle!
That tail wagging is absolutely adorable. I wonder if Pencils ever self-HNGGG’s?
Celestia, internally: “Oh no, not again.”
My theory: Physics.
Future!Twilight’s tail is four times longer, very likely thicker, and therefore exponentially greater in both volume and mass. Most hair stylists will agree that greater mass requires more energy to move. Therefore, wagging it like the HNNG-inducing filly above probably requires conscious effort on Future!Twilight’s part, and if she’s out of practice, she’s likely to pull a muscle!

your current filter.You used to wag your tail?
Why don’t you do that anymore?