I like the question and the comments by the previous poster, but I want to pont out some small details in lines 4-8 of Shelley's short poem "Ozymandias" that may indeed support the theme (or moral, or even cliche) of "pride comes before the fall." The poem describes the head of the statue of the long dead king (or pharaoh) as follows:
Half sunk, a shattered visage lies, whose frown
And wrinkled lip, and sneer of cold command
Tell that its sculptor well those passions read
Which yet survive, stamped on these lifeless things,
The hand that mocked them and the heart that fed.
The poem states that the facial expressions on the statue capture the essence of the man whom the statue represents, and these facial expressions are hardly ones of humility, compassion, or anything else that we might see as the opposite of pride. In fact, that "sneer of cold command" suggests to me that the ruler was just about as full of himself as he could be, and the very order that a huge statue be erected in his honor (a statue showing that very sneer) is a sign of his excessive pride.
To end my post in a summarizing statement, as did the previous poster, I think it's possible to say that the statue's head fell and shattered because it was so huge and so high up -- much like the man represented by the statue, who built himself up so much ("king of kings," indeed!) that he had nowhere to go but down. For the record, I don't normally like reading literature for moral lessons or reducing the meaning of literary works to what often sound to me like cliches, but in this case, such an approach has some merit.
For a metaphor, what about the "big head" in the poem. The literal big head is the shattered "visage" of the statue; as metaphor, it might refer as well to the king's excessively inflated sense of importance.
For alliteration, there are a few more that haven't been mentioned. One line has a repeated "h" sound -- "The hand that mocked them and the heart that fed" -- and later lines have other repeated consonants: "boundless and bare" and "low and level." Alliterating words don't have to be right next to each other.
I would not exactly say that the theme is pride goes before a fall. To me, that implies that pride causes the "fall." I think that the theme is more that everyone, no matter how important, becomes unimportant in the end. Ozymandias did not cause his own downfall by being proud. He "fell" simply because time passed.
There are a few examples of alliteration in this poem, lines like "cold command" and "survive, stamped."
To me, the whole poem is a metaphor. I think the statue itself is a metaphor for fame and importance.
I would probably preference the idea of "the personal response" is something that is impossible to achieve. There are many different and divergent personal responses to Shelley's poem. I am sure that this can be seen in the responses that have been posted in this setting. The metaphor of the broken and decrepit statue that once meant so much and stood so powerful is a wonderful statement on what it means to be human. In contrast to the Neoclassicists, who believed that human achievement and human greatness would stand the test of time, I think that the Romantic thinkers believed in the idea that human beings' time is temporary and passing. To make the life led as something meaningful and not waiting for immortality to make a judgment, to "seize the day" as opposed to standing in wait of it, is where the metaphor of the broken statue has a great deal of meaning. In terms of the relationship between pride and a fall, I think that there is a great deal of truth to this as the statue which is meant to commemorate "the king of kings" is deserted, isolated, set apart from all else and is crumbling. This helps to bring the idea that outside of pride, ruling and kingdom without meaningful accomplishment is not power in its own right nor is it representative of what strength is. The notion of pride helps to connect to the overall theme that anyone who rules in the hopes of being "king of kings" is going to suffer the fate of Ozymandias in the poem.