In the Iliad, when Hephaestus is making a shield for Achilles what is the point of all the different pictures he puts on it?

Hephaestus shows so much on the shield; the heavens, the earth, the sea, and the pictures of two cities with all the activities of civilization in the Bronze Age: festivals and weddings, legal disputes, warfare, animal husbandry, agriculture, and, finally dancing -- that in essence the god fashions for Achilles the whole world in miniature.  Thetis asked Hephaestus to make this armor for Achilles because Achilles will die soon.  Hephaestus says, "How I wish I were able as surely to hide him away from/dolorous death, at the time his terrible fate overcomes him,/as now beautiful armor will be his, such as hereafter/many a mortal will wonder to look at, whoever beholds it." (335)  Thetis cannot save her son from his early death, but she can give him the most wonderful shield ever made, showing all the things of earth that he could have ever enjoyed, and which he will soon miss when he is dead.  There is also some foreshadowing in the images, for one of the cities pictured is being besieged (like Troy), and a herd of cattle is attacked by ravaging lions.  There is some irony, too, as Hephaestus, the "twice lame cripple" (338) makes an elaborate scene of dancing.  The god cannot dance, but he can sculpt the best dancers out of gold and tin on a shield for Achilles.  Both Achilles and Hephaestus have something represented on the shield which is denied to them.   Source: Homer. The Iliad. Trans. Rodney Merrill.  Ann Arbor: U of Mich. Press, 2007.