I’ve always said that Cersei Lannister was the single greatest and most degenerate sociopath in the entire series of novels. She is also the Queen Mother of degeneracy and should have long ago been hung by the neck until dead. She is vile, not in the common usage of the term but in the accurate usage of the term, and she is a communicable disease.
Of course the other events in this episode were equally good (which I will not now mention), for the most part, and this was definitely the best episode of this season, the Battle of the Bastards being the next best.
But yes, even Jamie Lannister, a definite degenerate himself, must now fully recognize the twisted nature of his sister and that she is every bit as “mad” as was the Mad King.
If he has any sense at all he will behead Cersei as Sansa and Jon should do to Littlefinger, but will not.