Looking Gunterish 2002.
The AI model I used might have referenced Gunther photos. AI models are trained on photos. The checkpoint files are typically around 6 GB or so in size. You could train a model just on bridges, Ferraris, etc. One AI model could not encompass everything we have in real life. The file would be too huge.
An AI model trained only on Arnold photos would really be useful to update older photos with minimal changes to the physique. Unless they come out with a general purpose AI model that can upscale and remove all the noise and add missing details without changing the overall shape of the body.
I've tried a few upscaling software and they have their limitations. Remini is amazing when it comes to upscaling faces, but it sucks with bodies and everything else. At least last time I tested it. I read that My Heritage Photo Enhancer is also great for upscaling photos and adding missing details. I have not tried it myself.
Here's a My Heritage example. Remini can achieve about the same results.
https://blog.myheritage.com/2020/06/myheritage-photo-enhancer-goes-viral-one-million-photos-already-enhanced/Gigapixel is not as great for faces, better with bodies. But not as amazing as Remini / My Heritage are with faces.