1. Open the camera in VRChat and place it somewhere in front of you
  2. Navigate to your profile page in the full menu
  3. Click your user icon to bring up the menu to select a new icon
  4. Any area where the user icons and the VRChat camera overlap will be blacked out
In the attached screenshot, you can notice the camera sticking out from the left side an top of the menu, and that matches the shape of the blackout box appearing over the icons.