Okay either I'm stupid or not seeing the "relativistic effects".

This looks the same as on my device.

I was expecting some distortion or bending of the background?

> AR + camera warping don't work together, unfortunately – browser API limitations.

So, you either choose AR and see the simulated emission from around the black hole, properly warped/boosted – but the camera feed remains flat, the browser itself does the overlaying.

Or, alternatively, choose the camera mode, and see the warping of your camera feed.

Not both at once!