Final answer:
The literary device in the phrase 'O, she doth teach the torches to burn bright!' is a metaphor, which makes a direct, implied comparison without using 'like' or 'as'.
Step-by-step explanation:
The phrase 'O, she doth teach the torches to burn bright!' is a metaphor, which is a literary device that makes a direct comparison between two unlike things without using 'like' or 'as'. Unlike a simile, which makes a comparison using these words, a metaphor implies the comparison directly. This line suggests a woman's beauty or perhaps her presence is so striking that it outshines even the bright light of the torches.