From the article, it's not an actual sleep emote though. Look at what he describes:

Check out this Lalafell, enjoying a moment of respite after battle.
Or this Miqo'te, who no doubt just enjoyed a relaxing dip in the water!
It's not an actual sleep emote. It is more of a relax one. I suspect the /command was merely a poor choice. They might be better off using /relax for it, since that is what it appears to be. I for one, love how the female miqo'te looks in the pic, as well as the lalafell. I've no problems with the emote personally.