I was actually contemplating if I should post this as a bug, but I guess it's one of those quirky things in Glitch that I should accept as is. But if it could be improved, then I guess it's worth posting here.
Currently your avatar's expression changes depending on certain words you type via chat. In summary, I've observed that the following words can animate my avatar's facial expressions:
surprised face = huh / wtf / :O / O_o
laughing face = joy / LOL / :) / :D / hahaha
angry face = grr or >:( or :(
afk sleeping = typing "afk"
Maybe the sad face emoticon should generate a frowning (or crying) animation. I'm not sure though, but I remember vaguely that the game did have the crying animation way back into alpha. Having the sad face give out an angry expression may lead to some misunderstood context.
PS: Also typing anything starting with a slash ( / ) will return the message unknown command. Yuh, tried typing a few emoticons to see if any further animations are available and discovered that in the process.
PSS: I don't know if there are words that can trigger the animation for looking back, climbing, or that strange expression that your avatar gets when teleporting. If you know, please provide. Having my avatar animate at will is kinda fun.
Again, no big issue here. Just my 2c worth of suggestion. :D