The phrase suggests a dynamic familiar to many: a younger sister whose swagger and insolence are both a source of frustration and a magnet for attention. "Bratty" is an ambiguous word—pejorative when tossed at someone as an accusation, affectionate when traded among friends or siblings as a provocation that promises mischief. That ambiguity is the engine of persona-making online. Someone labeled "bratty" can be villain and protagonist, rebel and comic relief, depending on the viewer's appetite for drama.