Zuckerberg is a rich and high profile guy, so photographers capture many pictures of him, and news editors often find that choosing unflattering pictures of people their readers don't like is helpful for reach. This picture in particular was taken after he'd just finished testifying for 8 hours in a February trial, which I think would wear down the best of us, and even among Getty's extensive gallery of pictures taken then (https://www.gettyimages.com/detail/news-photo/mark-zuckerber...) this one is particularly unflattering IMO.