Known for her humanistic black-and-white portraits, Mary Ellen Mark made it her life's work to photograph those who didn't quite fit in. Whether that meant capturing the day-to-day life of Indian circus performers, the peculiarity of twins, or the loneliness of celebrities, she was drawn to people with pronounced personalities. “Attitude,” a new exhibition at the Howard Greenberg Gallery, explores this idea through 40 of the late photographer's images. “She was passionate and compassionate. Life mattered. Animals mattered. People mattered,” said Melissa Harris, the show's curator. The images focus on “self-possession,” Harris said, and highlight Mark's ability to make viewers “feel, without telling you what or how to feel.” The gallery has shared a selection of these images with The Atlantic, presented below.