When Emily White joined Instagram from parent company Facebook in March, her first order of business was to push Chief Executive Kevin Systrom into a room. “For the first two weeks, I locked him into a conference room and I said, ‘This is all about getting the mission on paper,’ ” Ms. White recalled. Two weeks later, Mr. Systrom had boiled down the app’s mission to one lofty, if perhaps hokey, phrase: “to capture and share the world’s moments.” It was a rallying principle that Instagram could now sell to its staff, its users and, just as important, future advertisers. Picture this: what will an Instagram ad look like? We could know as soon as next year. Plus, Facebook announces it will open a Twitter-like public feed. Evelyn Rusli reports on Lunch Break. Photo: Instagram. As director of business operations, the 35-year-old Ms. White effectively is the new chief operating officer of Instagram, the point person charged with turning a billion-dollar acquisition that has never made a cent into a real business.