"You are reading."
No, not really. Some young people have picked up this Ni habit, but there's no actual politeness tradition to it. If speaking to the King, you're expected to use Hans Majestät ("His Majesty") or Konungen ("The king"), which mirrors how Swedish used to express politeness through titles rather than pronouns.
This thread by Yours Truly contains a handful of useful tips on Swedish politeness, as well as some discussion among natives: https://www.duolingo.com/comment/5591933