The mirror section is a very simple section that controls whether the shader should appear in VRChat mirrors or not.
Show in Mirror
Type: Dropdown, Options:
Show In Both/
Show Only In Mirror/
Don't Show In Mirror
Mode to use for the mirror.
Show In Both: The material will be shown both outside and inside the mirror.
Show Only In Mirror: The material will only be shown inside the mirror.
Don't Show In Mirror: The material will only be shown outside the mirror.
Texture to apply to the base color only when in the mirror.