The bluestone is polished,
The beautiful fan flows with a subtle fragrance.
Answer: (1) Arranged as above, the first is a couplet.
(2) It can also be two lines in a five-character poem. There are eight lines in the five-character rhyme poem. The first and second lines are called the "first couplet", the third and fourth lines are called the "jaw couplet", the fifth and sixth lines are called the "neck couplet", and the seventh and eighth lines are called the "tail couplet". The chin couplet and neck couplet of the rhymed poem must be in opposition. The two example sentences you gave can be placed in the position of the chin couplet and neck couplet.
(3) Poetry writing requires charm and artistic conception, and these two sentences meet this requirement. The meaning expressed in the poem is: the beauty of bluestone comes from grinding; the beauty of the fan leaves a subtle fragrance. The fan here refers to the person holding the fan. Writing about fan means writing about the person holding the fan. She is obviously a beautiful woman. To say that she has a subtle fragrance on her body is to praise the charm of this woman's character. Where does the charm of this character come from? Author's answer: Just like bluestone, it is obtained through sharpening.