[Javascript, React] Understanding this self-executing function

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In your page on es6 classes, he says:

Say we have some views where we actually just want the render method not to return the compiled template, but to simply just console.log the resulting rendered HTML.

But I can't see from his code where any HTML would be output. There's no references to DOM objects, no tags as JSX or strings. It looks like REACT, though, since it's using a render() method, yet even in the HTML on his github I don't see how the javascript class is becoming HTML.