It was not a direct picture as a photographer may take. It is not proof of the existence of black holes any more than photos of UFOs are proof that aliens in mechanical devices somehow transversed the incomprehensible distances of many light years.
OK, but...
1. It was something
2. I hear you saying you dont know what it was
3. So it might have been a black hole
4. Others believed it to be a black hole.
And so it goes here on FR.
Yep and many thanks to Bill Robinson for all the fun.