The emoticon (%-= depicts a mad scientist with skewed eyeglasses and a long pointy nose, looking quizzically down and slightly to his left. This can signify Beaker from the Muppet Show, which by way of logic much like rhyming slang signifies the need for a drink. It can also be used to signify that one has just split an atom, which is not done in polite company; the averted gaze may indicate shame, or a failed attempt at "who, me?" nonchalance. When displayed with some typefaces, the skewing of the eyeglasses is lost, and the effect is of a donnish creep staring down his nose at the viewer; in this case, (%-= can and should be taken to indicate contempt, or in some cases intestinal discomfort.
Sometimes it looks like a stoop-shouldered beatnik in a beret.