The themes that are at work in Sylvia Plath's "Mirror" are truth and dishonesty and the waning of beauty over time.
"Mirror" is a short poem written by Plath in 1961, a time in her life when she dreaded the idea of getting old. The poem reflects this fear and her emotional state.
There is a line in the poem that says "I am not cruel, only truthful". What she means is that the mirror never lies and, as "a little god", it is capable of see it all. In this sense, the mirror is omniscient, as opposed to the "liars": the candles and the moon. Furthermore, there is a line in the poem that says "Faces and darkness separate us over and over" where she refers to the passing of time and how fast a young girl can become an old woman. Over the course of the poem, there are several lines that reflect the fear of growing old and the fading of beauty.
