Video lags a little, as Quicktime was recording it at the same time. Usually there will be no visible lag. Hence, to offset this lag, I sped up the video.
Figure 1: My Mirror Patch
Webcam input > pfaces recognition > light sensor > output video
I wanted to tweak the patch, such that if a face went too near the screen, a sound will bang out. However, I could not construct the automated response; otherwise, by mouse-clicking on the toggle button, the sound will ring out.
Figure 2: Mirror patch with sound edits
Will try it again if time allows.