Every card in a Lenormand deck carries a small inset of an ordinary playing card in one corner, and the Moon carries the 8 of Hearts.
Why the deck has thirty-six cards
Taken together the insets across the deck make up a complete thirty-six card playing pack, running from the six to the ace in each of the four suits. That is not a correspondence scheme laid over the pictures afterwards. The deck was published in Nuremberg in 1799 as a race game called Das Spiel der Hoffnung, the Game of Hope, generally attributed to Johann Kaspar Hechtel, and the insets meant the same printed sheet could be cut up and used for ordinary card games as well. The pictures were the board and the playing cards were the pack.
What the suit adds
The 8 of Hearts belongs to the suit this atlas records under love, emotion and relationships. It is a pip card. In playing card cartomancy the numbered cards are generally read as circumstances rather than as people, and the number is read alongside the suit.
Whose name is on the box
Marie Anne Lenormand died in 1843, and the deck was named after her by publishers afterwards. She did not design it, and there is no evidence that she used it. The name is a bookseller's attribution attached to an existing German game some decades after both the game and the woman had appeared, and this atlas records the system under her name because that is what it is called, not because she made it.