An activist investment firm won a shocking victory at Exxon Mobil. But can new directors really put the oil giant on a cleaner path?This story was written by Jessica Camille Aguirre and recorded by Audm. To hear more audio stories from publications like The New York Times, download Audm for iPhone or Android. Subscribe today at nytimes.com/podcasts or on Apple Podcasts and Spotify. You can also subscribe via your favorite podcast app here https://www.nytimes.com/activate-access/audio?source=podcatcher. For more podcasts and narrated articles, download The New York Times app at nytimes.com/app.