Why can use Redux here simply with store={store}?

in the following codepen, what is the use for the redux code in this codepen? what is the difference if not use Redux here? if i delete all the redux code, and it comes the same result. 2nd question, why add then the whole redux code works?

I changed a few code e.g. const ADD = ‘ss’ in the codepen, but still run to the same page and result, so I suspect that the Redux is not fired even Provider is used, any idea and explanation about this? this question is for the http://hysterical-amusement.surge.sh/ under React Redux 04

Either the pen’s author does not understand how to use Redux, or this example is a work in progress.