This is a secret mini-game of WoW. Like how /gems was built into EverQuest, and cost the lives of many a group as their healer was trying to beat their old high score.
So the game is to see how fast you can type /jamba, unclick the characters who are not currently playing, scroll down, and hit [Push to characters].
It's harder than you think when you're doing it for time trials.
Of course, when they log back in you bettah remember to click them once again, otherwise they won't tell you how much XP they have or take the same taxi as you or anything.