Twitter has made a change to its apps and website, grouping together tweets that are mentioning the same news link. This is in an effort to make news more prominent on the social media site, in its attempt to become more like a news site and less of a social media website. The way it'll show up now is, with the link at the top and the tweets mentioning that link below it. That way you can see who mentioned that link, but it'll only show tweets from people that you follow. So you won't be seeing tweets from every single person that mentioned the link, just those you follow.
In the past few years, Twitter has been focusing more on being a news website, instead of a social media website, and even has live news broadcasts from partners like Cheddar and Bloomberg. This was initially to keep users on the site longer, but it also adds more substance to the network and gives Twitter an identity. Users have always been able to share links to news articles and such, but now the site is making it easier to see these articles and read the articles. That is definitely a good thing for news publishers, as publishers are looking for ways to drive more traffic to their site, and Twitter is a big part of that push.
Twitter's move into news hasn't been all good, however. It has made plenty of mistakes along the way, which is not surprising, and it isn't just Twitter that has had this problem. But Twitter has done a good job at fixing these issues and making sure that they don't happen again, which is a good thing, as Twitter is showing it is learning from its mistakes. This new feature, where it is grouping tweets together below the link, is available on Android, iOS and Web right now, though it doesn't appear to be available for every single user right now.