How does word choice affect the emotional impact of “She Walks in Beauty”? Pay special attention to connotation rather than denotation. Use evidence from the text to support your response.

This small masterpiece by Byron could be considered a textbook guide to writing poetically as well as, as is usual in Byron, naturally and almost conversationally.
The first line, stating that "She walks in beauty" (italics added) instead of simply stating that "she is beautiful" or "she possesses beauty," suggests a kind of higher dimension into which the poet's love has entered, above the cold earthly world. Similarly, the comparison of her to "night" rather than "day" implies some degree of mystery about her. It's too ordinary, Byron seems to be saying, to employ the usual means of describing a beautiful woman as being "bright as day" or with a similar phrase. The "night" connotes something more interesting and possessing a deeper attraction.
In the second stanza, the characterization of her "nameless grace" implies something exceeding one's ability to describe it—a descriptive adjective is beyond the poet's ability. Also, in saying "one shade the more, one ray the less," the poet is suggesting that both shade and light are generated from within his love, not granted to her externally—since we have already pictured her walking "in the night." "Raven tress," though perhaps sounding somewhat conventionally poetic, also contributes to the connotation of that which is above the ordinary, above earth-bound human nature.
The last stanza, of course, is a kind of summation, and it seems the least striking poetically of the three. "The tints that glow," however, because this is simply an unusual way of getting across the idea of the radiance of his beloved's face, again impresses the reader with a suggestion of a magical quality, leading up to the beloved's "mind at peace with all below / A heart whose love is innocent!" The central point about his beloved's character comes at the very close and seems to tie the entire poem together into a single thought.
"She Walks in Beauty" demonstrates a recurring feature of Byron's verse: his ability to establish an almost conversational tone and simultaneously—through suggestion and the appropriate use of specialized, poetic language—to give an impression of transcendent beauty and divinity in women and in human beings overall.