Note to Romeo and Juliet, 2.2.27-28: "As glorious to this night, being o'er my head / As is a winged messenger of heaven"

To Romeo, Juliet looks like a bright angel in the night, who makes the night "glorious," a form of the word "glory." One meaning of "glory" is the circle of light represented as surrounding the head, or the whole figure, of the Saviour, the Virgin, or one of the Saints (Oxford English Dictionary), which is the meaning that Shakespeare has in mind here.

Madonna and Child in Glory