The sigma is an open mouth in some contexts! that emoticon is used to express shock correct?
this might be a little difficult to go over if you aren't familiar with the visual conventions of anime or other forms of sequential art. nevertheless I'll take a crack at it.
∑(O_O；) - the whole face. we're already familiar with how parenthesis are used to delineate the boundaries of the face! ∑ - the part that's giving you trouble, this isn't actually a part of the face at all. it's being used to portray "shock lines" which are used in conjunction with character expressions to indicate that said character has just had a jolt of one kind or another.
no subject
this might be a little difficult to go over if you aren't familiar with the visual conventions of anime or other forms of sequential art. nevertheless I'll take a crack at it.
∑(O_O；) - the whole face. we're already familiar with how parenthesis are used to delineate the boundaries of the face!
∑ - the part that's giving you trouble, this isn't actually a part of the face at all. it's being used to portray "shock lines" which are used in conjunction with character expressions to indicate that said character has just had a jolt of one kind or another.