On the preprint proof of the cards, the text direction on the back and the front is reversed. Why is this?

Simply because this is the only way that we can print double-sided. If you take a landscape sheet of A4, draw a dot on the left-hand side of the front then flip it over along the short side, the other side of the dot will be on the right-hand side of the page.

Link to this answer: https://azaogames.com/en/faq/on-the-preprint-proof-of-the-cards-the-text-direction-on-the-back-and-the-front-is-reversed-why-is-this/