It is very natural to fear death. We fear what we do not understand, and by its very nature, death can never be individually understood. We fear aging because it represents the ceaseless march of time towards inevitable annihilation. Decay is the physical symptoms of aging, and a tangible benchmark of the fore-coming of death.
Old animals are not always easily distinguishable from the young of their respective clade, but old plants are always easy to identify. They wear their age on their sleeves, so to speak, through distinct changes in color and size. This mount of brown and yellow leaves was a perfect subject to exemplify aging, looking almost like a graveyard in stark contrast to the vibrance of the healthy leaves hanging above. The ominous mood is only amplified by the jagged, encroaching shadow.
Memento Mori.