Something inside my iPhone 12 camera?

I just bought a used iPhone 12 and when I received it, everything seemed good. However the selfie camera in the dark seems a bit alarming. I've been a Samsung user my whole life so I don't know if it's normal but a selfie taken in the dark with flash is super grainy. When I checked the cameras, I noticed these weird web-like marks on the inside of my camera. Is this normal?

Sorry for whatever reason, I could not get a better picture than this.