I feel like, in general, the fact that the question was inspired by a Tweet shouldn't be relevant to how the question is presented. In this case, your question boiled down to "Can you explain this plot?", and for a typical question of that form, we'd expect the asker to link to the paper (here, Thorne et al. 2021, mentioned in this Tweet) and explain what they do and don't understand about it. Even if none of the Tweets in the thread link to the paper, it might be possible to track it down the same ways you'd try to find the source of any other diagram.
It would certainly be good to link to the Tweet if it provides additional necessary context or is unfortunately the only source you're able to find for the diagram, but those both feel like edge cases.