This emotion represents being Shocked.

Have you ever had that moment where you're in your nude clothing (Underwear, bras, etc.)
while visitors are in your house? Or maybe when you go to school in 
your pajamas, finally notice your wearing your sisters/brotheres shirt,
or go to the streets bare footed? This skin explains it all and the
picture below it :3

  <--- I had to post this on Devian art to copy it xD