Working as a stage set designer I’ve found that there’s a general feeling of harmony or non-tension if the major lines and curves on the stage are in some simple ratio to the height and width of an actor and./or to the frame (the proscenium or the size of the lighted area). A section of wall twice as wide as an actor is tall, for example, or a platform 1/3 actor height situated 1/4 of the way back from the front edge of a thrust stage (obviously in a steeply raked house; a curve whose radius is 3x an actor height or a wall that rises from 1/3 to 2/3 proscenium height; that sort of thing). The golden rectangle tends to be “quiet”, i.e. not call attention to itself, so it can be a good ratio for a doorway or window if you want the audience to focus more on what comes through it than on the door or window itself.
There’s a general feeling of tension or instability if the major lines and curves are in more complicated and/or inconsistent ratios, especially if they’re also asymmetric.
So I’ll generally get all the basics figured out (seating areas, traffic paths, driving into and out of corners) and then, thinking about mood and feel of the play, I often tinker a bit to get onto those ratios. But they don’t dominate or drive the design; they’re just more like tuning the instrument after you build it.
