Flash Sentry wasn't there for his sister when she got her cutie mark, but he went to see her as soon as he got the chance. Even so, he worries that he and Scootaloo may drift apart over time.
With that in mind, they begin to talk about what their cutie marks have in common.
A super late reaction to Crusaders Of The Lost Mark, as well as the fact that Scootaloo's cutie mark bears a few surprising similarities to a certain other pony's mark.