In the first line of this extract, the mirror is compared to a lake.
Both the objects have the quality of reflecting the image of what appears before them.
It is not out of cruelty but truthfulness that I reflect exactly what I see without any intention of hurting anybody.
In this extract, the mirror is described as an ‘exact’ because it shows and reflects whatever it sees in all its exactness.
It does not hide, tone down, twist or distort what it sees as the human beings do.
When the poet says, “I have no preconceptions,” he means that the mirror is absolutely unbiased. Besides, in the same stanza, the mirror has also been described as ‘unmisted’ because it is ‘clear’, ‘objective’, ‘dispassionate’ and ‘unprejudiced’ in reflecting what it sees.
Knowing fully well that moon and candles would not reflect her with all truthfulness, she turns to them to get (though false) a mental satisfaction that age was not catching up with her.
In this extract, the woman once again examines herself in front of the mirror for reassurance.
The woman starts crying because she has become very old. Also may be she is fretting and fuming at the loss of her youth and beauty.
This reveals her to be a woman of weak and vain character whose life becomes miserable because she cannot accept the reality.