How does Percy Bysshe Shelley explore the theme of change in 'Ozymandias'?

Described as a mocking and sneering “King of Kings”, Shelley creates an arrogant and proud persona for the titular Ozymandias. This is further emphasised by the dscription of his statue as “vast” and "Colossal": Shelley's word choice connotes an enormous and imposing presence designed to incite awe. However, when the speaker learns of the statue, it has become “trunkless” and “Half-sunk”, reduced to simply “legs of stone” and “a shattered visage” by the destructive effects of time and weather. Sibilant sounds connect these changing descriptions of the statue, emphasising the process of its decay over time. Through the changed state of the statue, we can infer that the leader it represents has fallen from power and grace. Thus, in 'Ozymandias', the image of the statue can be viewed as a metaphor for the evolving nature of power and society.