It’s part of the webcam feed provided by the OS to apps on the latest macOS. This means the effects apply across all apps. You can increase lighting adjustment (aka Studio Light) and depth of field with sliders in the system menu bar, as well as toggle thede reactions on and off. They’re on by default.
For what it’s worth the lighting and background blur effects are really good, much better than the tuning built into Zoom. I’m leaving the reactions on too for the comedy for now but I’ll probably turn them off eventually.