When they were just thirteen and eleven years old, sisters Chloe and Halle Bailey started posting videos of themselves singing on YouTube and quickly built a following. Their covers often went viral—their version of Beyoncé’s “Pretty Hurts” even caught the attention of Beyoncé, who brought them on tour as her opening act.  Now, with two albums and five Grammy nominations behind them, the sisters are for the first time working on separate projects: Halle is starring as Ariel in an upcoming remake of “The Little Mermaid,” and Chloe is releasing a solo album, “In Pieces,” later this month. Chloe Bailey spoke with the contributing writer Lauren Michele Jackson at the New Yorker Festival in October about the mixed blessing of social-media stardom. “When we program our minds to think about being No. 1 … it really suffocates you and it stifles the process,” she says. “Right now, I’m just creating to be creating, and I have never felt more free.”  Plus, the lost New Jersey photographs of Henri Cartier-Bresson. In 1975, the French master photographer spent a month documenting New Jersey, which he called a “shortcut to America.” Why did the pictures disappear?