The Brick and Mortar mitts are seamed up the side when you have reached the desired size.
These mitts are seamed as mirrored. That means when viewed from the top the bricks are mirror images of each other.
These mitts are seamed as identical. That means when viewed from the top the bricks look the same on both hands.
The difference is when they are out on the hands. Mirrored are the same on top of the hands and on the palms.
The identical will have the top of the left mitt will look like the palm of the right mitt and vice versa.
These mitts here are all knitted but the same idea applies to the crocheted ones as well. Which seaming will you choose?