You should be able to generate some graphic fractals by touch (or multi-touch).
Now try it with your Sidecar/Duet Display/Wacom touch/whatever.
Good Luck!
PS: You may try it also on some Windows device with touch support (both notebook/convertibles/Surface). It should work, because Windows, unlike macOS, natively supports touch.
Just try this website on any iPhone or iPad: http://borismus.github.io/mobile-web-samples/browser-ninja/
You should be able to generate some graphic fractals by touch (or multi-touch).
Now try it with your Sidecar/Duet Display/Wacom touch/whatever.
Good Luck!
PS: You may try it also on some Windows device with touch support (both notebook/convertibles/Surface). It should work, because Windows, unlike macOS, natively supports touch.