What is the purpose of the stanza?

example: The purpose of this stanza is to develop a general time and place - setting - for 'The Raven'. In this stanza, the month is identified as a cold one and an unsavory one. Additionally, a fire is dying as a person seeks to grieve through reading a book. He is grieving over the loss of his love, Lenore. At this point, because it's so early in the narrative poem, no real tension - stress - has been developed, but we can begin to wonder over how the character will cope with the loss of his love. After all, he does refer to her as a "rare and radiant" maiden.

Open here I flung the shutter, when, with many a flirt and flutter,
In there stepped a stately Raven of the saintly days of yore;
Not the least obeisance made he; not a minute stopped or stayed he;
But, with mien of lord or lady, perched above my chamber door—
Perched upon a bust of Pallas just above my chamber door—
Perched, and sat, and nothing more.

The purpose of this stanza is to introduce the Raven into the narrative and establish its mysterious presence. The narrator opens the shutter and the Raven quickly enters, drawing attention to its majestic and significant appearance. The stanza also highlights the lack of respect or acknowledgement from the Raven, as it does not make any gesture of greeting or pause in its movements. The Raven's choice to perch on a bust of Pallas, the goddess of wisdom, adds to its enigmatic aura. Overall, the stanza creates anticipation and intrigue as the reader wonders what significance the Raven will hold in the story.