In the poem, Byron writes that daylight is "gaudy."
He does this to prove that daylight is overly bright and showy. His love is not like daylight -- she is not bright and showy.
That's why she walks like the night -- she does not need to flaunt her beauty. Her beauty is natural.
Yes if it is not your work then it is plagiarism to copy and say you did it. you always want to rephrase your work. (:
Fiction, nonfiction, and poetry.