Sorry I wasn't clear. The top and bottom edges of the card are short edges. The left and right edges of the card are the long edges.
On every card, you have that arrow that points "to the previous room", which is always at the bottom of the card when viewed on screen.
Similarly, all the "dead end" cards always have an entry point that leads to the bottom edge of the card (when viewed on screen).
I was trying to suggest that if the arrow sometimes pointed at the left or right side of the card, or the dead end's entry/exit lead to the left or right of the card ("a long edge"), instead of always the bottom, that would increase the variety of layouts.