Spaced repetition memory prompts alone are a poor communications medium, but the Mnemonic medium gives the prompts order and embeds them in a larger whole by embedding them in a prose narrative. This context allows readers to build understanding in an authored, structured manner. The narrative also gives the prompts a more salient purpose, which is important because Deep understanding requires (and is a result of) intense personal connection.
See also the discussion in Expanding the scope of memory systems: what types of understanding can they be used for? within How can we develop transformative technologies for thought?
Matuschak, A., & Nielsen, M. (2019 0). How can we develop transformative tools for thought? https://numinous.productions/ttft