The original sentence of the poem should be "Wan Jian never regrets, smiles at each other and despises kingship", which is from the kingship chapter of The Little Matchmaker of Fox Demon, but since it is not a quotation or adaptation of any poem, I try to relate the literal meaning to the story of Fox Demon and try to explain it.
Royal family: it should refer to the royal sword of the rich, which should imply power and status.
Light: Maybe it means to despise or ignore?
Smile at each other: it seems to be "smiling at each other." The original intention is that the two sides look at each other and smile to describe their feelings. I guess people are omitted from the poem.
So the explanation should be this: I don't regret it when I die, but I just hope that when we meet, I can see you smiling at me. Compared with this, even power is not important to me.
We are just a new Macey, so please forgive me if I don't answer well.