Standard night shot mode, moon selected to get the correct exposure, sitting down to avoid movement. I've done some astrophotography before as well, I have a mirrorless and some longer lenses. I don't think the pixel phones put a png of the moon there, that was a Samsung thing.
https://www.theverge.com/2023/3/13/23637401/samsung-fake-moon-photos-ai-galaxy-s21-s23-ultra
I've honestly taken better shots of the moon with my real camera. I'm just amazed at what a phone can do handheld, in horrible lighting conditions. Here is the shot straight out of the phone.
I made it grayscale, tweaked shadows, highlights, sharpness and contrast.