Final answer:
The irony in the inscription on Ozymandias's statue lies in the contrast between the king's boastful claim of power and the desolate scene of ruins, emphasizing the temporary nature of human achievements.
Step-by-step explanation:
The inscription on Ozymandias's statue ironically claims great power and enduring legacy, yet the irony lies in the fact that all that remains is a broken statue in the middle of a vast, empty desert, effectively conveying a message of hubris and the impermanence of human achievements. The phrase "Look on my Works, ye Mighty, and despair!" directly contrasts with the surrounding "lone and level sands" that stretch far away, suggesting that Ozymandias's empire has vanished and that his works have not withstood the test of time. This contrast highlights the theme of the transience of power and the inevitable decline of civilizations, no matter how grand they once seemed.