Also see A first look at Twitter’s new prototype app, twttr | TechCrunch
"The basic idea from October is still the same. In the flagship Twitter app, replies appear in a chaotic jumble. On twttr, replies are threaded in a way that might be familiar to users of Reddit. As more users interact with a tweet, additional replies are indented, giving the conversation a better visual hierarchy. Replies from the original tweeter are shadowed in black, rather than the blue of other responses, giving them added weight.Twitter’s new beta app offers threaded replies, and it’s fine | The Verge
Another notable change in this design is the decision to remove engagement counts from the design. You won’t know how many likes or retweets a response got unless you tap it, a step most users will never take. The idea is to avoid rewarding people for attacking one another with zingers in the way that more visible engagement counts do.
Finally, the new design hides some replies under a “show more” button. That includes replies that “could be abusive or spammy,” a Twitter spokeswoman said in an email."