The concept is called persuasive writing, of which my English teacher absolutely drilled* into us the five paragraph format for:
The conclusion is basically a rewrite of the introduction, that includes the TL;DR versions of the body's answers or reasoning.
Every essay or paper designed to be persuasive needs a paragraph at the very outset introducing both the subject at hand and the thesis which is being advanced. It also needs a final paragraph summarizing what's been said and driving the author's argument home. –Writing Guide: Introduction and Conclusion; usu.edu
The title, "Why and how to convince (you and) your mom to buy a Pixel Tablet," wouldn't be as
catchy persuasive. Furthermore, if you condense all of these into a single concise paragraph, you've created the article's abstract. This is where you'd find words like hitherto and aforementioned (which is what I though you were after).
I personally found this writing style indispensable for science fair papers which also have an introduction (problem), as well as a body (procedure) that is to be persuasively backed up with data (results), the culmination of which can be found in the conclusion, and the TL:DR version of the whole thing: an abstract.
** Take a look at the (1-3-1) formatting of my answer above the block quote: There's this(1). Here's what it is(2–4). Here's why there is this(5).
Introduction: "by mentioning a particular item/person/anecdote or similar" (1)
Body: "continues to lay out the subject" (2–4)
Conclusion: "and in the end refers back to the "thing" in the beginning of the text" (5)