What is the effect of Plath's choice to write the poem from a mirror's perspective?

It is
startling and disorienting to have this poem written from the point of view of a mirror. A
person looks into a mirror to receive reassurance or confirmation about their own appearance or
reality. We expect that if we see something amiss in our appearance in a mirror, we can quickly
fix it. We expect a mirror to provide a reflection of ourselves and nothing more. Beyond its
purpose in reflecting us, a mirror seems empty.

It is startling, therefore,
to think a mirror could look back at us, see us, and judge us, not merely reflect us. It is
disorienting that we might not only see ourselves but that the mirror itself might have a
consciousness that could see us clearly and objectively.

A mirror is an object women look into both to see themselves and, in the second
stanza, to try to see into their own soulsto see their depths, as in a lake. However, Plath, by
personifying the mirror and giving it a personality, a consciousness, and...