When you make a skin, you actually only get to make 1 arm. The game then copies the arm you drew, and mirrors it onto the other one. Look around - every skin you have EVER seen has the same thing on both arms, because that is how the game works.

In the case of characters with specific traits such as gloves/armor/details on a specific arm, the skinners have to choose whether to leave it in or not, or come to a 'compromise' design between the two sides. On this skin, I figured that the claw was too important to the character, so I put it in knowing that it would be on both arms, rather than leave it off.