The big exception to this is the TIE Fighter, a ship that Cantwell knew needed to look different from the other ships. For audiences, he wanted this Imperial ship to be one that would be “instantly perceived as something Alien and somewhat timeless.”
This helped create an immediate visual juxtaposition: the Rebel ships would generally look familiar (the space equivalent of ‘50s hot rods, basically), but the TIE Fighter would look unfamiliar and therefore more threatening.
Speaking of threatening, Cantwell revealed that the panels on his TIE Fighter design were, first and foremost, meant to look scary. “Above all the ship and panels had to be mysterious and threatening.” He has a point, too: these Imperial vessels just look menacing in a way that other ships don’t, which is part of that first film’s overall visual language.