Let the fairy lady light a handful of incense and roll it up. One of them is straight. Why?

Honey, it's nothing. It's purely accidental. This phenomenon you are talking about is superstition, which is collectively called "looking at the head of incense", that is, judging whether it is good or bad according to the different forms of burning incense is actually not allowed. The length of burning incense is related to the quality, material, density, whether there is wind, oxygen distribution uniformity, ignition time, etc., but this does not mean anything, and the immortal will not enlighten you in such a low-level way (because since an ordinary person is dead, the strength of his soul can only hold a dream at most, but can't change the length of burning incense. Remember, faith is completely different from superstition and folk custom.