The Speaker is talking about a painted bay window of the West. Like the sun's color. He is saying like the lady is shinning when she is in the window. The evening star is the star of love and rest.
The speaker is saying that all her clothes are radiant. Also saying behind the dark screen of the far away trees. With sleep and sweet dreams of love.
His sweet evening star like venus.
My morning and evening star of love.
My best and gentalist lady. She is fair as the planet above. When it is night you rest. When it is night time there is barley light.
The first stanza of the poem gives the reader a good visual painted oriel of the West. He is telling the sunken sun's color. The part where he says "Like a fair lady at her casement, shines" he is saying that when she is in the window she shines.
The second stanza of the poem he tells about her garments. Behind the dark screen of the far away trees. When she sleeps with slumber and sweet dreams of love.
The third stanza of the poem he is using a metahpor comparing to the evening star (venus).
The fourth stanza of the poem both of the moring and evening star of love. Love is magical.
The fifth stanza of the poem it is a metaphor by saying that his best and gentlest lady is as that fair planet in the sky above. Like she doesnt do anything wrong.
In the sixth stanza of the poem when it is night you retire until you rest. When it is night time there is barley any light, besides the stars and the street lights.