not sure, but i think when they stopped resembling the original characters when you turned them sideways, :) :D :P etc so a smiley was, and may still be an emoticon representing happy, but a smiley-styled face that has a party hat, streamers but a sickly looking greenish face means "hungover from partying too hard the night before" and i just can't see anything on the keyboard to express that lol
Caption this Meme
