This (orthomagic) square is remarkable in that its 16 pieces form a so-called setiset or self-tiling tile set. The latter is any set of n shapes, each of which can be tiled by smaller replicas of the complete set of n shapes. In this case, each of the pieces is composed of four 2×4 rectangles. Hence a larger copy of any piece can be made with the four row or four column targets, which are of same shape (4×8). Each of the pieces can thus be tiled using smaller duplicates of the entire set of 16. More on setisets can be found here.
