I actually have a video for this one because for once I made a digital that didn't need me to do anything.
The swinging from side to side is part of how I programmed it, rather than an odd filming decision!
I filmed most of the interactions from behind the screen so I could get a good shot without inhibiting people.
This is actually 2 projects in one.
The big one used an Xbox Kinect 2 sensor to pick up distance data I could then map to coloured dots in a rotating 3D cloud using a digital art coding thing I use quite a bit called Processing.
The second one on the door also uses Processing, but this time with a webcam converting onlookers faces into scratchy line drawings in real time. Well I say "real time", it actually ran a bit slowly because I was using my aging laptop which couldn't quite handle the load.