This is a cross stitch of a solution to the Picture Hanging Puzzle, which asks how you can having a picture on n nails where removing any one nail causes the picture to fall. It is intimately connected to Brunnian links, as each nail is effectively an unknot in the link. This is a symmetric presentation of a general construction, where loops can be passed through each other in such a way that they each depend on their neighbors to stay together. I've also made a wooden version with four removable pegs and a length of rope to tie around them. 