This post is purely for my own understanding of production design - but may contain something useful for any other people who may be presently undertaking a similar role:
The term 'Production Designer' was coined in 1939 in respect to the work of William Cameron Menzies on the film Gone with the Wind, for the amount and calibre of design work he single-handedly accomplished on set. Previously, and often subsequently, the person(s) with the same responsibility had been called "art directors," but it is clear nowadays that this term is often both insufficient and inaccurate.
From early in pre-production, the production designer collaborates with the director and director of photography to establish the visual feel and specific aesthetic needs of the project. The production designer guides key personnel in other departments such as the costume designer, the key hair and make-up stylists, the special effects director and the locations manager (among others) to establish a unified visual appearance to the film.
Production Designers have one of the key creative roles in the creation of motion pictures and television. Working directly with the director and producer, they must select the settings and style to visually tell the story. They are the person ultimately responsible for the overall look of a filmed event.
Some of the crew who work in the art department under the production designer include: art director, assistant art director, set designer (draughtsman), set decorator, concept illustrator, graphic designer, model maker, although these roles can sometimes be interchangeable.
The set decorator, often someone with experience in interior decoration, finds decorative items for the sets such as furniture, wallpaper, knick-knacks and lighting fixtures. Working under the decorator are buyers, as well as a crew of set dressers who bring the items to the set, arrange furniture, hang curtains and “dress” the set.
A prop master coordinates with the production designer, but also works closely with the director and actors to provide the items handled directly by the actors such as newspapers, weapons, musical instruments and food. For the most part, the prop crew, along with an on-set dresser, maintain the integrity of the production designer’s vision during the shoot and manipulate the items for the camera.
[adapted from wikipedia.org]
Clearly, my role in Potato Cakes includes several components of 'art direction', none of which can really be simplified. However, Production Design is probably the closest summation we are going to find, as I dont think the term 'creative gopher' would resonate with too many folks out there... do you?