Why can a container that is too small make a floral arrangement look top-heavy?

In the context of floral decoration, a container that is too small can make an arrangement appear top-heavy because the plant materials overpower the vessel.1

In floral design, the container is considered an integral part of the overall composition and must be related to the flowers in scale, color, and texture. When the container is undersized, it fails to provide the necessary visual weight at the base to support the arrangement, creating a sense of instability. To maintain proper proportion, designers often follow traditional guidelines, such as the Japanese rule that an arrangement should be at least one and a half times the height of the container. Using a container that is too small disrupts this balance, causing the composition to look lopsided or top-heavy rather than harmonious.12