Although she's one of the biggest movie stars on the planet, Angelina Jolie is mostly unavailable on social media. To date, she's only been featured in a single photo on the platform.
Elle Fanning, her co-star in the "Maleficent" films, shared the photo on her own channel. The main purpose of social media, especially for celebrities, is to share a more human side. It's understandable that Jolie, who's already incredibly famous, wouldn't see it as a necessary part of her work as an actor.