The part of the article that says that it can project an image that only children will see (due to their height) reminds me of the Audio Spotlight which is supposed to allow you to aim a beam of sound in a narrow area so just one person, or a few people can hear it without disturbing anyone else. This allows you to create a silent exhibition space with open informational kiosks where only the person in front of the kiosk hears what's being said.
A combination of the two could lead to interesting James Bond type secret messages being displayed with audio intended for only one or a handful of people.
