The discussion centers around the visibility of blueshift effects in a simulation of a black hole's event horizon. Participants express curiosity about whether the expected blueshift of background light is represented in the simulation or if their expectations are incorrect. Specifically, there is a mention of a significant blueshift exceeding 43 times, raising questions about how such a shift could be visually perceived. The conversation suggests that the simulation may have omitted this effect to focus on the warping of the background sky's geometry, leading to uncertainty about how these visualizations incorporate the blueshift phenomenon. Overall, the dialogue highlights the complexities of visualizing relativistic effects near black holes.