Like a political candidate, a brand is complex. It evolves, adapts, and in spite of its best efforts it shows different faces to different people. However, like a political candidate, a brand builds a following most successfully when it demonstrates a preference for some causes, ideas, and personality traits over others.
Some brands have a brand bible, which dictates guidelines for the brand’s visual style.
But which traits are essential and which are extraneous variables? A chart like this builds a boundary around the brand, but it also shows the designers which walls are movable. Where may designers innovate? The intent is to encourage evolution rather than revolution because many designers, especially inexperienced ones, tend towards turn-the-brand-on-its-head-to-make-headlines revolution* and they need to be steered back on brand.
Drastic changes in a brand’s look should only happen when the brand is reinventing itself. Such was the case for Microsoft and USA Today. Such was not the case for GAP because GAP was not positioned to engage a new demographic.
*You should see the wildly off-brand ideas I came up with when I started out!