What are two appealing features of Shelley's "Ozymandias?"

The use of multiple voices that Shelley uses to narrate the poem and the universal message that ends it become two of the most appealing features of "Ozymandias."  

There is a powerful story to Shelley's poem. It is enhanced in the way that it is narrated. The opening line where the speaker meets a "traveller from an antique land" is extremely appealing.  On one level, the speaker is narrating a story within a story.  The speaker is sharing the narrative as we listen, for he tells it as it was told to him.  This feature is reflective of the Romantic movement, of which Shelley was a part.  

Romantic thinkers believed that truth existed in all aspects of the world.  There is much to be learned from formal instruction as there is from random stories.  The poem's opening enhances this because life's truths are being communicated by a stranger, a random "traveller from an antique land."  The poem's opening helps to frame its meaning for the reader.

I think that the end message of the traveller's story is another appealing feature of the poem.  The power of time offsets Ozymandias's boastful declaration of power.   When we see the "colossal wreck" that is all that left of the statue, it is a reminder of how time withers everyone and everything. Shelley uses the poem to communicate the temporal nature of human beings.

Ozymandias was arrogant and boastful.  He truly believed that he inspired fear in people.  However, only decay and disrepair remains.  This message is a powerful one as it communicates the reality that underscores all of human hopes and dreams.  While Ozymandias saw himself as immortal, the reality is that "Nothing beside remains."  Time will continue, even when we do not.  This philosophical statement is one of the poem's most appealing aspects.