profoundness+of+English+or+Italian+sonnets

In stanza 3 of this poem Collins writes "We write on the back of a waterfall or lake, adding to the view a caption as conventional as an Elizabethan woman's heliocentric eyes" (7-9). Collins is comparing how diminutive our writing is compared to what was conventional in the Elizabethan times or in English sonnets. The meaning of heliocentric is "with sun central, from center of the sun" (Encarta Dictionary). Collins is using this word with "Elizabethan woman's" as to say, her eyes are as beautiful and powerful as the sun. That sounds pretty profound compared to "adding to the view a caption" as you may do on the front of a postcard. That does not sound very eccentric to me.