Twitter introduced a new design for replies today that ranks conversations in your timeline according to signals including whether you follow the person who replied and whether the author replied. The personalized ranking means that different people will see a different set of replies by default, although you can still expand the tweet to see every reply. The feature is new to mobile, devices, though Twitter previously brought this design to the web in … June 2015?
— Twitter Support (@Support) November 29, 2016
The sort-of-new take on replies ranks more popular replies higher than others, so if you deliver a sick burn to a brand, more people will see it by default. The new design also includes conversation counts, so you can see which tweets are generating the most abuse and harassment at a glance. (Also fun and productive conversations, sometimes!)