[PopePompus]

There is no chance this is being faked. I've been playing with the astrophotography mode on a Pixel 4 XL in a remote country location with no cell phone connectivity. A single 4 minute exposure is able to record stars down to about magnitude 9.5. A single exposure can detect the Crab Nebula, or the two brightest satellite galaxies of the Andromeda Galaxy (M 32 and NGC 205). To fake such results without internet connectivity would mean that the camera software would have to have an internal catalog of about 250,000 stars, with accurate colors and coordinates. It would need the size and shape of nebulae, the contours and brightness of the Milky Way, etc. When I add multiple frames, I see fainter stars appear, as they should, so the internal catalog would really need millions of stars, most of which would not show up unless the user carefully aligned multiple individual image and summed them. This is not being faked.

[Jyaif]

You do realize that with 2 floats to store the position of a star on a sphere, that's like 8 MB per million of star? With compression you can almost certainly get away with something like 2 bytes per stars.

And an other solution is to simply store a bitmap of the sphere around earth.

[PopePompus]

It also shows the positions of the planets correctly, so it would need to have an ephemeris, or planetary orbital elements. Meteors and satellites show trails across the star field. At some point simulating all of this would be more complicated than really doing it.