The quote come from the poem Ozymandias by Percy Bysshe Shelley:
I met a traveller from an antique land,
Who said—“Two vast and trunkless legs of stone
Stand in the desert. . . . Near them, on the sand,
Half sunk a shattered visage lies, whose frown,
And wrinkled lip, and sneer of cold command,
Tell that its sculptor well those passions read
The question is when is a good time to you use an ellipsis instead of a comma or dot, because I feel that an ellipsis doesn't do anything here. Am I wrong? A comma or a dot could have had the same effect, is there a kind of stylistic effect here that's at play and I am unaware of?