That famous photo of the scientist with the ring image on their laptop screen was exactly that: after all 4 teams had tuned their algorithms to make sure they c

That famous photo of the scientist with the ring image on their laptop screen was exactly that: after all 4 teams had tuned their algorithms to make sure they could accurately image the simulated data (ring, crescent, disk, double point source)... then all 4 teams imaged the actual data. That was the first moment, Eureka! Now that you've read the correct paper, you know that. You could have also learned it from the news releases, as it was an important part of the science.