In Sonic Rainboom Rainbow Dash was obsessively trying to reproduce the titular stunt. But back in The Ticket Master she makes no mention of what has since become her signature move. So what changed, why is Rainbow suddenly trying to reproduce a trick she'd probably written of as a one time fluke years ago? This story gives us an answer - because she once again pulled off a sonic rainboom, this time as an adult. So now she knows it wasn't just a one time thing and can be repeated if she just figures out how.
This story gives a great explanation for why Pinkie's joy buzzer trick upset Gilda so much; the buzzer was built for much thicker pony hooves, which Gilda doesn't have, so when the buzzer goes off on her, Gilda is in legitimate pain.
