The entire poem is rife with rich imagery. First, the speaker compares the shell to a ship that has been abandoned. As he beholds the "ship of pearl" he wonders about the years that it took to create such a vessel, "Year after year beheld the silent toil / That spread his lustrous coil;" and wonders further what might have caused the hearty worker to leave his home: "Still, as the spiral grew, / He left the past year's dwelling for the new...".
Later, he gives the shell as much signficance as the gods of old, the imagery here is of the god Triton whom, as he contemplates the empty remains envisions "From thy dead lips a clearer note is born / Than ever Triton blew from wreathed horn."
The speaker is flabbergasted by the beauty and complexity of such a seemingly insignificant creature. The image in the last stanza is of a beautiful mansion, and the hopes that he, a much more complicated creature than the nautilus, might be worthy of even greater feats. He concludes, "Build thee more stately mansions, O my soul...Till thou at length art free, / Leaving thine outgrown shell by life's unresting sea!"