The "open unlidded eye of the golden day" is an Epithet or Logos. A further explanation is below.
A descriptive word "Epithet" seems to be an adjective that accompanies or takes place rather than just a title. This phrase shows a character's characteristics, generally a protagonist or maybe even a deity. This is because of the literary roles of such an epithet.
Logos, ones indicates that the majority for their idea, would be a sort of appeal.
So the statement is supplied in some kind of logos.
