The 'look of disapproval' is the description of the emoticon ಠ_ಠ
Used widely across a myriad of chats and social network forums and sites over the last decade, it is made of a Sanskrit based Dravidian language Kannada alphabet.
Unlike most 'smilie' emoticons, it is always expressed on its own with no qualifier or text. As a reaction element, it has become the default response to inappropriate snark, unsolicited perversion, disappointing behavior, and overreaching ebullience.
While on its own and no context one might not see how it actually represents a look of disapproval, and yet in usage it does that exactly. Part of the reason it does may be due to the 'classic' look of disapproval in situ, which always requires the use of spectacles and a librarian-- or teacher-- looking over the top of said spectacles right at you, who has just slammed a book closed, or is in the middle of spitting a wad of paper across the room.