A friend sent me this image. 2 SUP fins installed backwards. While they look cool, ideally the fins should be facing the other direction for more efficient water flow.
The slant should be facing backwards thus allowing water to flow back off the end of the fin and board. In the current direction they will increase drag and not allow the paddler to be as stable as they could be.
Below, is the correct direction for the fins to face. Again imagine water flowing over the top of the fin towards the back of the board.