“When you set the table, you can’t put the chopsticks upright in the bowl because it looks like incense, which people burn at funerals, so it’s bad luck”
I think this superstition also is a way to honor and respect the dead. Positioning the chopsticks in such a way is bad luck, but it is also an affront to the serious nature of funerals, where the incense is burned. The informant can’t remember when she was evert taught this, it’s just something she’s always known. This belief would also create an easy situation where outsiders can be recognized, because they would not know this custom by heart like native Chinese people do.