This is an augmented shadow puppet display now at the EMP/SFM. It’s an interactive installation that adds monster features to your shadow. (Monster features as it’s part of a horror-themed exhibit.)
The circles, fangs, eyes, and hairs are added to one’s silhouette dynamically as you stood in front of a large projector/screen. It seemed to be shape-based: curved surfaces sprouted hair or halos, long shapes open at one end were given teeth, and circles were filled with eyes.
I really wanted a logical, consistent silhouette, so I played with poses and posture. The best result I got was from looping my arms above my head, which resulted in giant, misshapen eyes. Playing with it felt a little like magic.
Although too short to participate directly, that little boy loved the shadows anyway.