I see :-)

Thanks, I was afraid Vuforia introduced a new parameter to manage, but I can just set to OFF and do not have to manage it.

Video reflection (also sometimes referred to as "Mirroring") is an option that can be useful when used in combination with FRONT camera, as it allows to mirror the image (same as if you were in front of a mirror, where the display of the device represents the mirror).

Of course, you can use it in combination with the BACK camera too, but this is usually a less interesting use case.