In the book "Fire and Blood," the queen and her children are terrorized by Blood and Cheese. The kids are awake the entire time. Cheese makes Helaena choose which kid he's going to kill; then, after she chooses, he kills the other kid just to mess with her. The pair of them really take their time with the whole affairs. They come across as movie villain serial killers, unconcerned with the actual mission, and totally not at all worried at the thought of the entire castle coming after them at a moments notice.
Compare that to the show's version. Cheese is clearly afraid, being motivated by money to get out of his debts. Blood is motivated by duty to his former commander and hatred for the Hightowers. The prince is an attack of opportunity; they wanted Aemond, but he wasn't an option. They don't waste time scaring Helaena; why would they? They know how much danger they're in. They have a mission. They get her to identify the prince, who is asleep, and they immediately take him out. In their haste, they even forget to guard Helaena, who immediately takes her other kid and flees.
I'm seeing a lot of fans insist that HBO "pulled their punches" with the episode, that it isn't as "impactful." Nevermind that GRRM wrote "Fire and Blood" as a history book, from the perspective of characters who admit their sources aren't always reliable. Nevermind that the book version is absurdly unrealistic, depicting two amateurs masterfully pulling off a prolonged assassination and torture session of most of the royal family, solely for the sake of being as brutal as possible.
The fans of "grimdark" often expect that type of stupid shit, and when they don't get it in an adaptation, mistake it for "pulling punches" instead of just trying to be more realistic.