Media hyped black hole images will show a whole lot of nothing. Look at the simulations put out by the research team showing what they expect to find, nothing, at least at the location of the black hole. Which is just fine. A black hole is a region of space time from which light cannot escape. The escape velocity for their gravitational field exceeds the speed of light. In relativistic terms their effect on space time is such that falling towards the center of the black hole is as inevitable as the flow of time in the forward direction. As such the base standard expectation of a black hole image is to see nothing.
What is interesting is what we will see surrounding that nothingness.
Although I would not be completely surprised if the actual image shows the black hole to “shine” from light that just barely skims the event horizon. The path of the light having been bent into our line of sight from some distant star or stars.CLICK FOR IMAGE. image Credit: Chi-Kwan Chan, Event Horizon Telescope.
This image highlights the simulates the expected features of the accretion disk and outflow near Sgr A*which would result from combining images taken at different wavelengths/frequencies of light. Precise observations of the accretion disk and outflow near a black hole could help us to refine our models of gravity by testing them in a regime of intense gravitational fields. Precise enough observations of light that just barely escapes the event horizon could, someday, tell us something about the structure of space time and of QFT interactions in a region where both gravity and quantum are important. Such images could, someday, provide indirect test of theories which seek to unify general relativity with quantum field theory.
For now, let it be enough to marvel at having any image at all of such an elusive region of space-time as a black hole. This will be a great achievement worthy of all the fanfare it gets no matter what it finds.
Scientific prediction: We will see results which exactly correspond to completely classical General Relativity with no hint of physics beyond any standard models. Never bet against Einstein.