The square knot device is displayed on the uniform to denote that the wearer has received the corresponding award. The award is usually in the form of a certificate and many awards also include a medallion or other momento.
A knot emblem does have left and right sides. The rope loop over the rope ends always is to the wearer's right. The diagram here shows how the knots would look to someone looking at the shirt. The knot images on the rest of this page all show the correct knot direction.
Square knots are to be worn centered directly above the left shirt pocket. The first knot should be placed with its bottom edge touching the top seam of the pocket flap. The next two knots are placed on both sides of the first knot in a straight row of three knots. Additional knots are placed directly above the first row with bottom edge touching top edge of the existing knots.
From the diagram, you can see that as additional knots are earned, single and double knots on a row need to be resewn. For this reason, some people prefer to place knots right-justified with the pocket edge.