Answer:
The second option: By implying a similarity between the ruins of Ozymandias civilization and the Rapa Nui's ruins.
Step-by-step explanation:
While walking among the head statues the author noticed how some of them were fallen and broken, some appearing complete and yet so far away from any habitation that he compared them to having the empty gaze of Ozymandias.
He also touched on how empty the island is and lamented on the disappearance of its ancient culture, but yet the statues still stood bearing the same expression they were carved in, and quoting Shelley in his comparison: "the heads still look terrifying, their expression sneering, 'Look on you mighty and despair'"