Eighth grader Emma Pichardo, a student at M.S. 50 in Brooklyn, didn’t know what the Black Lives Matter movement really was until a teacher showed her a documentary about 17-year-old Trayvon Martin last year.

Six years ago, Floridian George Zimmerman fatally shot Martin, his neighbor, as the unarmed teenager was walking home. Zimmerman, who is white and was a neighborhood watch volunteer at the time, was widely thought to have racially profiled Martin.

The documentary was the backdrop to Emma’s decision to participate in a local T-shirt designing contest, open to all New York City students, for the national Black Lives Matter Week of Action. The event encourages teachers and students to engage with the 13 principles of the social justice movement born from incidents of black men and women having fatal encounters with white police officers.

Those 13 principles are diversity, restorative justice, globalism, queer affirming, unapologetically black, collective value, empathy, loving engagement, transgender affirming, black villages, black women, black families, and intergenerational.

The local contest is largely organized by city public school teachers, and the winning T-shirt design is sold online.

Emma’s design last year — a silhouette of a black woman, surrounded by bright splotches of colors and the words “Black Lives Matter” — didn’t win. So she tried again this year, with a slightly different approach: an all black-and-white design with the same silhouette in the center, surrounded by the 13 principles.

Last week, local organizers cast the most votes for Emma’s design among a total eight submissions. It was notable that Emma won, said her art teacher, Brittany Kaiser, who provided feedback as Emma worked. Her teacher encourages students to enter these contests but has found with high-school participants, it’s tougher for middle-schoolers to come out on top.

Emma wanted the winning design — now on a T-shirt for sale online — “to show people that we should all have the same rights.” She hoped people would see it and find a positive outlet for their anger, sort of like she did.

The key part of the silhouette, she says, is its large afro.

“I want black women to see themselves for what they are and not what the social media shows them, because a lot of women are going through that phase that, like, they see women in social media and they want to be that type of person,” Emma said. “I want them to be themselves and be confident about their body shapes and their features and all that.”

Emma’s designs, according to Principal Benjamin Honoroff, are part of the school’s larger culture of connecting art to social justice. One example of that is an elective activist arts course that’s open to students.

Parents and staff have been supportive of the culture, Honoroff said. When the school’s Twitter account tweeted about Emma’s winning design, there were a few responses, almost all positive. But one user replied, “Shouldn’t we be teaching ALL LIVES MATTER?” — a reference to the slogan created in backlash to the Black Lives Matter movement.

Honoroff and Kaiser said they haven’t received any complaints about the contest.

“If I did, I would explain that most students are already aware of Black Lives Matter as a current event — it’s in the news, it’s a current event, it’s a social movement — and bringing issues of racial justice into the classroom acknowledges and affirms students identities and also engages them in critical conversation about the world around them, and I think that engagement is always beneficial to students,” Kaiser said.

For Emma, the contest is one step down a career path she hopes to follow. She has auditioned for elite LaGuardia High School of Music & Art and Performing Arts and wants to make a career out of visual art — painting and sketching for now and maybe dabbling in photography.

I want my art to have the power to change people’s mindsets,” Emma said.