Metaphors are used almost as much as personification in this passage, as the entire second stanza compares the mirror to a lake, but even before that metaphors are distinctly present. The mirror calls itself “the eye of a little god,” by that point in the poem, Plath has made sure that it’s clear that the mirror is distinguished as completely objective, “unmisted by love or dislike” and “not cruel, only truthful.”
What should the readers pay attention to is how the characters say, behave and feel in every line or how they were able to react in each scene or part. This will allow them to notice how the characters evolve or how they were able to develop in each scenario that is happening on the character's life as the story goes. For this is essential in reading a story or a book.