What are JOINT TWEETS on Twitter? Can you create one?

an interesting example of a tweet like here's just like a tweet from Porters but people are asking is it means that now there are joined tweets so as you can see this is an example of it just comes from two accounts so one account and another one I'm not sure if this is like a new feature or it's it's been rolled out to everyone so you have no idea actually how that so people now are asking about it hmm uh so I have no idea actually uh yeah how to do it of course if you just try to tweet yourself it won't be possible for you for you I guess at this moment so you can tag someone but then it will be a personal tweet not a joint tweet so hopefully this feature can come in in future uh yeah it's interesting idea I think it's already there in some other social media