Playing cards pattern tricks
Observe the pattern / design of your playing cards deck. Compare the appearance before and after you turn it 180 degree. Observe the back side and the front side of your playing cards. Do you realize any differences when you turn it 180 degree?.
The secret behind the front side of playing cards. (the "face") You were already knew that the face of each card carries markings that distinguish it from the other cards in the deck.
Secret behind the card deck pattern - How to
Figure 1.1 - 1.2 ...


That difference also exist on other cards face. There are many cards design but much alike that difference are also exist on A,3,5,6,7,8,9 of Heart, Spade and Clover and also on 7 Diamond. And for some design that difference also exist on Jack, Queen, and King of spades.
The secret behind the back side of playing cards. That difference also exist on some of back design / pattern of playing cards decks.
Figure 2.1 - 2.2 ...


Actually the less obvious the difference that exist the better, because that also means the less chance your audience aware of it.