Question

why does tje mirror insist that it was truthful

Answer 1

becoz it does not have any preconception about anyone

Answer 2

The mirror first describes itself as “silver and exact.” It forms no judgments, instead merely swallowing what it sees and reflecting that image back without any alteration. The mirror is not cruel, “only truthful.” It considers itself a four-cornered eye of a god, which sees everything for what it is.