I hope this doesn't ruin a magic moment, but... seems like this image might actually be incorrect. There's a more modern paper in the description of this video that analyses the data with a different approach and they get something that looks quite different.
https://www.youtube.com/watch?v=cdeee7tZ8QY
In any case, one way or the other, we got the correct image of such blackhole now. Just it's not this one.