What does that represent? There was never any question in plastic art, in poetry, in music, of representing anything. It is a matter of making something beautiful, moving, or dramatic - this is by no means the same thing.
"Ahu" are stone platforms on which many moai sit. There are 313 known ahu and 125 of these carry moai. The biggest, Ahu Tongariki is 220 m (720 ft), and had the most (15) and tallest moai.