It suggests that in order to truly understand a situation one needs to observe what is happening at the site where work actually takes place: the gemba (現場).
Since real value is created at the shop floor in manufacturing, it espouses the philosophy that this is where managers need to spend their time.
Genchi genbutsu is sometimes referred to as "Getcha boots on" (and go out and see what is happening) in English due to its similar cadence and meaning.
[2] This concept quickly became so universal that new managers instinctively knew that they had to "walk around" to achieve high effectiveness levels.
Toyota has high levels of management presence on the production line whose role is to "know" and to constantly improve.