The innocence and optimism of childhood are what stand out first in a new exhibit of portraits at the Martha’s Vineyard Playhouse. The wide eyes and shy smiles of youngsters, photographed in Africa, Afghanistan and Martha’s Vineyard invite the viewer to grin back.

The lives behind their smiles are not always so sweet. Some of the off-Island children in the photos were rescued from slavery and exploitation.

“She was picking coffee on a plantation in the Rift Valley when I first met her,” Len Morris said of a young Kenyan girl in one close-up. “She was probably 9 or 10.”

Mr. Morris, a filmmaker, and his wife and creative partner Georgia Morris are the founders of Media Voices for Children, a Vineyard-based human rights nonprofit that advocates for the young. The playhouse exhibition, titled Our Children, brings together portraits of rescued children by Robin Romano with those of Island kids by Vineyard photographer Melissa Knowles.

Filmmakers and founders of Media Voices for Children, Len and Georgia Morris. — Mark Alan Lovewell

“The common ground for this show is not the duress or the backstory, the common ground is the beauty and resilience of children,” Mr. Morris said. “Vineyard-Afghanistan, side by side, works for me.”

Another thought emerges when looking at these images of kids from such different spheres: On one side of the world, children are a labor force. On the other, they’re consumers. Coffee is still a product of child labor in multiple countries, Mr. Morris said. So is cacao — the key ingredient in chocolate.

And while the U.S. Department of Justice has recently stepped up enforcing laws against importing goods made with child labor, Mr. Morris said, child trafficking and exploitation continue to be intractable evils in large parts of the world.

India, for instance, may be losing up to half a million children a year, according to the 40-year-old New Delhi-based Bachpan Bachao Andolan (Save Children Movement). Abducted or sold, they become tiny, easily-replaced components of the country’s economic machinery.

After the reception for the photo exhibit, the audience watched footage of Children of Bal Ashram, a documentary by Len and Georgia Morris and Petra McCarron. The film reveals both horror and hope with respect to children’s rights activism, opening with scenes shot 23 years ago of small children toiling in brickyards and gravel pits, girls tethered to looms and boys gluing sequins to bracelets in dingy, cramped workshops. But today those scenes are no longer to be found in the vicinity of Bal Ashram, a children’s refuge established in Rajasthan by Bachpan Bachao Andolan founders Kailash and Sumedha Satyarthi.

Children of Bal Ashram, which made its debut at the Martha’s Vineyard Film Festival last year, is a heartening documentary about the Satyarthis’ work. Along with rescuing close to 88,000 children — some 9,000 of whom they then raised at Bal Ashram — the couple has encouraged young people to be activists for their peers. The film shows teenagers and children leading mass marches, speaking up at community councils, opposing child marriages and insisting on education for girls.

The Satyarthis’ mission, for which Mr. Satyarthi won the 2014 Nobel Peace Prize, has also led to the establishment of hundreds of “child-friendly” villages where child labor and child marriage no longer take place, all children attend school and a council of children has a voice in village government.

From the Vineyard, Georgia and Len Morris are also working to end child exploitation with their films and other initiatives, such as a presentation for American schoolchildren called Behind the Barcode.

“It’s aimed at educating kids about the economic consequences of their spending,” Mr. Morris said. “They’re a target demographic.”

Our Children is on display in the Martha’s Vineyard Playhouse lobby during box office hours through Feb. 6. For more information visit mvplayhouse.org and mediavoicesforchildren.org.