
... when the shapes of objects all look the same (worst of all friendly and rounded) it's hard to understand at first glance that they have different consequences. Make the big decisions look significant (in this case, like clicking it too fast might cut your finger!) and it breaks the autopilot behavior. It's almost like a visual version of onomatopoeia, objects can look like what they are. It’s similar to using ‘red’ for cancel buttons or ‘x’ to close windows, just a bit more dramatic!
As the tools we develop increasingly get deployed globally the challenge of understanding a users common 'frame of references' increases dramatically. The considerations we apply today only touch the surface when you consider your user to be just about everyone. Hooking UI into deep-rooted human instinct means we anchor on at least a small part of everyone's frame of reference.
If you'd like to watch the full video here's the link. Also check out the Kiki & Bouba effect if you're not familiar with it.