When it comes to design what is the difference between mandala and kaleidoscope?

The only similarity is that there is a lot of apparent symmetry in both.

A real mandala is designed to resonate with human visual perception to create specific vibrations. These vibrations calm and focus the nervous system is specific intentional ways.

If you get that out of a kaleidoscope it’s accidental, and it will probably be at a more mundane level than you will from a genuine mandala.

As far as mandala goes we’re talking the genuine Yantra article here not some new-age acid-trip brain-fart, which are nice to look at and all but are not likely to be a scientific design.