Currently after defeating a boss our characters usually give a Joy emote for the victory. As seen with certain bosses though (most noticably the 8-man raids) this is not always the case though!

What I think would be nice would be for certain content to have all the characters in the duty instead do their Victory Pose in sync, including our own character doing so instead of having the short delay. Given that we get it in the story, 4.0 and onwards could certainly use this without any issue player-side if it matters whether the character in question has the emote.