Tales from Ponyville: Chapter 3, Page 6

First, Rainbow's expression in the first panel is so wonky. She looks like a Peanuts comic character when they shout 'Uuuug!'.

Second, Rainbow Dash looks so bad-flank in the panel before the last one. Her cloud necklace looked like a pendant for her awesome cape/blanket. So she looked very superhero-y.

Finally, this is the same kind of behavior that ended up almost messing up winter in 'Tanks for the Memories'. It's selfless determination taken a bit too far.