I really wanted to title this thread Eccentricity, but I couldn't quite squeeze Aspect Ratio into that lovely, so much sexier, word. Aspect ratio is the symbolism that every picture can't escape from. Even the cave paintings end up having it. Why? Here is Rudolph Arnheim to take you through the options. I'm not going to indent the following, but it is all from Arnheim: "The dominant pull of gravity makes the space we live in asymmetrical. Geometrically, there is no difference between up and down; dynamically, the difference is fundamental. "... Every one of the edges that make up an enclosure is, in our terms, a combination of centricity and eccentric extension. It generates tension-loaded fields that reach into the outer and the inner neighborhood, and these fields diminish in strength and increasing distance. "... A rectangular frame makes the eccentric axes dominate and thereby favors the comings and goings in goal-directed activity. In representational painting, a landscape or crowd scene will normally call for horizontal extension, whereas a full-length portrait or a waterfall calls for verticality within the picture. It makes the portrayed figure taller and the waterfall narrower and longer. In a landscape of horizontal format, the waterfall would lose some of its intensifying support, but it would also acquire a particular accent through the contrast it offers with the horizontality of the total scene. "... The walls of a room may be called [a] frame. If the room is cylindrical — as, for example, the interior hall of a baptistery — its center claims the place of greatest importance. This is true also for square-shaped rooms, where the equality of the eccentric axes supports centricity. A rectangular room will emphasize eccentricity and will have some of the connotations of a passageway. It will make a table look longer or shorter, depending on which way it is placed. It will also give the table the connotation of either conforming to the flow of action in the room or blocking it as a counteragent. "... The shorter walls serve as base of departure or as goal, depending on the direction of the room's movement, and the two longer walls form the lateral bed of a channel. "... circular enclosures underscore the detachment of subject matter from the environment. When religious images aim to stress their transcendence, they can do so effectively by choosing a format that estranges them spatially from a secular setting. On the other hand, the detachment from earthly gravity predisposes circular enclosures also for playful decoration and frivolity by evoking a "floating world," unencumbered by the burden of practical chores. "... The shape of the square enclosure and its internal structure are subject to the eccentric grid and therefore are intimately related to the vertical / horizontal framework of architectural settings. "... Not that it excludes spiritual subject matter; but just as the balancing center of the square tends to rely on the crossings of the linear coordinates, its subject matter has a way of elevating its theme by defining it through the crossing of the terrestrial horizontal with the ethereal upright. "... An overall stillness rather than pervasive turbulence is the mood that suits the format of the square.