There are several ways the traveler in Percy Bysshe Shelley's poem "Ozymandias" gains information about the King Ozymandias and what sort of man he was. The first source of information is the inscription on the base of the statue:
And on the pedestal these words appear:
‘My name is Ozymandias, king of kings:
Look on my works, ye Mighty, and despair!'
This inscription not only tells the traveler that Ozymandias was a king, but also gives the reader an impression of his arrogance, especially in the way it proclaims Ozymandias not just a king but the "king of kings" and greater than all "the Mighty."
Finally, the traveler looks at the expression on the face of the statue, and describes it as:
a shattered visage lies, whose frown,
And wrinkled lip, and sneer of cold command,
Tell that its sculptor well those passions read ...
In other words, the sculptor was such a good artist that a viewer, looking at the sculpture, gets a strong sense of the personality of the king it was portraying.