Paul Rand talk about designer’s role here, it’s interesting… although a bit old but still..
“Because graphic design, in the end, deals with the spectator, and because it is the goal of designer to be persuasive or at least informative, it follows that the designer’s problems are twofold: to anticipate the spectator’s reactions and to meet his own aesthetic needs”
(Paul Rand, A Designer’s Art, New Haven and London. 1985 p.xi)
Another one is from Paul Jobling and David Crowley (1996) which is another interesting view about designer’s practice is:
“In daily encounter with so much visual material, more often than not our experience of graphic design appears seamless and the myriad of images we confront so impenetrable that we scarcely take time to consider the ways in which they can signify the meaning of our won existence.”
(Graphic Design – Reproductions and representations since 1800)