Snapshot Settings Question

Can someone explain what "no post-processing" is for? I've never noticed it before and when I tick it on/off there is a difference in lighting/brightness in my preview, but is this something I want on or nah? I do a little editing when I save my pictures, if this matters.

https://preview.redd.it/x5s2bazm1q2e1.png?width=320&format=png&auto=webp&s=aa5751748b2eca519c99a3a19ed0f38cdd24b643