Ozymandias is a great libertarian political poem of ironic, rhetorical revenge upon the monstrous tyrant and his savage tyranny.
The poem begins with the image of "trunkless legs", all strutting pomp cut down. The "shattered visage" has preserved upon it the "frown" and "sneer" of cruel oppression and brutality which the sculptor, in an act of surreptitious and unnoticed resistance to power, has ironically turned into the lasting monument in contrast to the symbol of greatness the deluded tyrant desired.
The last lines, in their echoing and repeating vowels, spell and sound the emptiness of the king's domain. Shelley knew that one of the instruments of subjection was language itself - "cold command" – and here he turns his own rhetorical power against the tyrant.