Q1: Simple structured interactive machine which has multi-degree of freedom .
Q2: Recognize the position of the person and cover the floor with a screen to achieve the naked eye AR effect. It is more interactive than mine as it accepts different kinds of action and combines hearing with vision. It doesn’t show you all the results, which gives me a sense of mystery.
link: https://www.bilibili.com/video/BV1ZT4y17787?from=search&seid=13259788523842814622
it would be better to expand a little bit more in your answers, why you would be interested on these types of machines for example?