What this looks to be, is a combination of a few animation swaps and a finely tuned macro.
I've actually been looking at animations a fair bit the past few days -- so I can tell which are in play, because I was actually looking to do something like this eventually.
all_b_cbt_pistol_walk_aimed (there was also a firing version being used)
My first thought was that they swapped mood animations -- but having a ranged weapon equipped blocks those idle animations. So I'll assume they hid their chat box for a reason -- that they're actually swapping emote animations (and therefore spamming chat).
...So unless I simply haven't found a file where that'd be handled, I ran with my assumption that these are emote swaps.