When looking at the logo or the graphic symbol - business sign - of any enterprise, questions always arise. Whether the sign is still unknown or whether it is familiar, one will ask what this shape represents or what led it to be chosen, so that it could continue to represent the company to which it refers. In both cases, what inspires the questioning is: what makes a visual sign efficient? Since the brand name took on indisputable importance in the business world, there has been discussion of the force exerted by a company´s graphic representation, which makes it possible to identify the business and promote increased sales of the products associated with it. The purpose of this work is to present an interpretation of how a business sign attains this efficiency, knowing that this does not derive from its shape alone, but is conferred upon it based on a symbolic field of production - the field of design. Following in the footsteps of W.J.T. Mitchell, an author who has addressed aspects of an image´s functioning and, fundamentally, Pierre Bourdieu, who has made clear, by means of the theory of production in symbolic fields, the way in which a symbolic asset - an image - achieves recognition as legitimate, it is possible to understand that the efficiency of a business sign depends on legitimacy, which is produced in the relations between the various levels of this autonomous field of design, contrary to the designers belief.