In AE, you'd do it with Rotobrush to isolate the person on which the image appears. You'd then use the resulting matt as a track matte for the video of the images over the person, and use a combination of opacity and perhaps a blend mode.
Don't try using Rotobrush without running tutorials and a little practice. You'll fail. Rotobrush isn't intuitive.
KGAN (CBS) & KFXA (Fox) Cedar Rapids, IA