I suppose scientists will know how to photograph things with such strong gravitation that light cannot escape.
That isn't me, of course.
This will be a radio telescope image. They are not collecting anything from the visible spectrum.
It will presumably show the accretion disk, the distortion of light paths near the black hole, and the absence of light directly from the black hole. Something like this perhaps:
The apparent warping of the accretion disk to flow "above" the black hole in the image is actually light emitted from the back of the accretion disk being bent around the top of the black hole.
If you've seen Interstellar, the black hole shown
in that movie is close
to what scientists believe a black hole really looks like.
After they do the black hole at the center of our galaxy, they plan to get an image of the black hole at the center of M87
, that really huge galaxy at the center of the Virgo Supercluster
(of which our own local group of galaxies is only an outlying member).
What blows my mind is, they say that they are doing it next because these are the two largest
black holes in our sky in terms of how big the image appears from earth.
M87 is quite a good distance away from us. For the central black hole there to be the second largest-appearing one in our sky it must be unbelievably huge.