My ideas of both my characters and the people around them run the gamut. The males might be large/beefcakey like Arnold Schwarzeneggar, Michael Clark Duncan, and Dwayne "The Rock" Johnson, or they might be normal/fit types like Matt Damon, Robert DeNiro, and Denzel Washington. The women could be small/waify/even delicate like Holly Hunter, Alyssa Milano, or Kiera Knightly, or they might be buxom, Frazetta models like Linda Carter, Lucy Lawless, and Salma Hayek. And everything in between.
There SHOULDN'T be a single "look" to D&D any more than there should be just ONE way to play the game correctly. The art should run the gamut just as EVERYBODY'S conception of their PC's and NPC's will. You need cartoon AND photorealism, portraits AND landscapes, over-the-top action AND Tableaux.