It was called industrial design in those days.

They had round green buttons labeled “●POWER” since those days I think.

Not all Sony devices has green power buttons but if there’s a button labeled in green it powers up by pressing that.

https://www.jamesbutters.com/ has various examples of transistor radio designs, which could be considered Walkman predecessors.

And if you’re old enough, you may have experienced a SW transistor radio With a single mono earpiece giving you that feeling of being real time personally connected to the world far, far away from home. A precursor to the feeling of connecting to a far away BBS (bulletin board systems) and eventually the Internet.

Ha! The Sony "Pacemaker".

And to think some of those were actually built stateside... Now even Japan mfgs a lot of their products overseas.

No, that’s stuff we invented recently. Before it was just jam it in a box and see if it works.

Heh