Malala Yousafzai, one of Brooklyn Landmark Elementary School's "core value mentors," surprised students this fall by serving as the school's "celebrity substitute" on the YouTube show of the same name.

The Nobel Peace Prize laureate — honored at age 17 for championing girls' education in her native Pakistan — spent a day at the school teaching 2nd-graders and helping launch a major makeover of the school's outdated library and technology room.

Teacher Sabrina Brathwaite, who has taught at Brooklyn Landmark for six years, applied last spring for the school to be featured on the show, which partners with Amazon to fulfill wish lists for selected schools. She was delighted when the school, which is part of the UFT's United Community Schools initiative, was chosen and thrilled when she learned that Yousafzai would appear.

"The kids actually getting the chance to meet one of our mentors was super exciting," Brathwaite said.

Before the makeover, the library was rarely used and held shelves of old, disorganized books. The adjoining technology area had become a catchall for broken devices, and STEM materials sat unused because teacher Christopher Chin could not download needed apps on Department of Education equipment.

"The library is a disaster," Chin tells host Julian Shapiro-Barnum and Yousafzai as they tour the space in the 14-minute episode released on Nov. 5.

Chin and Brathwaite spoke to Yousafzai before she met her 12 2nd-graders. "They can smell fear, so let them know you're the boss," Brathwaite advised, drawing nervous laughter from the famous sub.

Brathwaite and Chin watched on a monitor as Yousafzai led a lesson on peace and compromise. The children donned black suit jackets and debated issues like whether outdoor play or screen time mattered more. They worked through disagreements, forged compromises and shook hands at the end.

The school's revamped library now features hundreds of new books, colorful seating and child-friendly stepstools. A bookcase labeled "Malala's Book Club" displays titles she wrote, including "I Am Malala," and others she recommends. The technology side includes new tablets and movable tables.

Chapter Leader Andrea Castellano said her 3rd-graders "fall in love" with Yousafzai each year during a unit on how children around the world access education. On the day the show was recorded, she and other staff stayed late to meet Yousafzai. "She's been an icon in our school community for years and her coming just seemed so fitting," Castellano said.

She added that Yousafzai thanked the educators. "I am so in awe of the work that you do as teachers," Yousafzai told them. "It is not an easy job."