meaning emotional absorption to be misappropriated as mental absorption

Misappropriated? Wouldn't 'grok' mean absorption of all kinds?

Personally, I like the word. It implies something more than simple comprehension or understanding. That said, I think it's misapplied here, exactly because of that difference. As an introductory tutorial, the reader is just beginning to understand the concept. It'll take much more than that to achieve what the word implies.