| Quote #1
She walks in beauty (line 1)
This is a funny way of describing someone – what does it mean to "walk in beauty," anyway? Is "beauty" some kind of cloud or vapor that the woman is walking in? Or is it like a comfortable pair of shoes?
| Quote #2
And all that's best of dark and bright
This woman's beauty takes the "best" things from both ends of the spectrum ("dark" and "bright"). And it's not just that she has a pretty face – her whole "aspect," or appearance, is harmonious and lovely.
| Quote #3
Thus mellow'd to that tender light
The balance of "dark" and "bright" in the woman's appearance sort of averages out into a "tender light." It's like she casts off a glow, but a soft one, or something.