Mine did this once to me last month while watching a youtube video but it hasn’t happened since, I joked about it being google’s top secret night vision mode but I’m thinking its some sort of software bug related to graphics rendering, maybe something funky going on with its GPU.
I also restarted my pixel 7 and it went back to normal so who knows what really causes it.
It looks bad compared to the iconic camera bar style they started with the pixel 6, and they changed the form factor to be more narrow and tall, RIP Passport form factor