In what senses is the mnemonic medium more than an annotation layer on ordinary prose?

A straightforward way to think about the Mnemonic medium is as “text plus.” You write a prose explanation, then you go back through it and annotate it with prompts which reinforce the key ideas. It’s much more interesting, though, to think about ways in which the combination creates a meaningfully new medium—where the questions push the prose around and vice versa. Are there powerful possibilities there, or is it just aggrandizement?