How is symmetrical balance created in a flower arrangement?

In floral decoration, symmetrical balance is achieved by placing similar flowers in identical positions on either side of an imaginary vertical axis.1

This technique creates a formal, static quality in the arrangement. Because the visual weight is distributed equally across the central axis, the composition appears stable and balanced to the viewer. While symmetrical balance provides a clear sense of order, it is often considered more contrived than asymmetrical balance, which relies on the subtle counterbalancing of varying visual weights to achieve a more varied and aesthetically pleasing effect.1