Eyeliner

The MacWilliams Eyeliner fits onto a support plate under the camera in much the same way as an autocue system. The interviewer sits beside the camera in the usual way and a 45 degree partial mirror reflects the interviewer's face so that it appears superimposed over the camera's lens. The interviewee makes eye contact with this image of the interviewer but is actually looking straight down the lens.

It's used to give an intimate feel to interviews where the contributor is in effect directly addressing the camera as in a "video diary" whilst still being able to engage with and respond to the interviewer.