One of the hallmarks of Frank Lloyd Wright's architectural style is its use of strong horizontal elements which stress the relationship of the structure to the land. Vertical lines communicate a feeling of loftiness and spirituality. Erect lines seem to extend upwards beyond human reach, toward the sky. They often dominate public architecture, from cathedrals to corporate headquarters. Extended perpendicular lines suggest an overpowering grandeur, beyond ordinary human measure.
Diagonal lines suggest a feeling of movement or direction.
Since objects in a diagonal position are unstable in relation to gravity, being neither vertical nor horizontal, they are either about to fall, or are already in motion, as is certainly the case for this group of dancers. In a two dimensional composition diagonal lines are also used to indicate depth, an illusion of perspective that pulls the viewer into the picture-creating an illusion of a space that one could move about within. Thus if a feeling of movement or speed is desired, or a feeling of activity, diagonal lines can be used. Horizontal and vertical lines in combination communicate stability and solidity. Rectilinear forms stay put in relation to gravity, and are not likely to tip over.