This is an example of what I call "sliver dropouts"; thin slivers of the puzzle that are dropped-out (not included with the puzzle), which together form a figure. The sliver drop-outs usually confuse the assembler when he or she is looking for neighboring pieces. But even when the assembler first realizes that there is a drop-out, he or she has no idea that there is a larger figure formed by the sliver drop-outs until all of the surrounding pieces are in place. Also, a figure formed by sliver drop-outs stands out much more than a figure formed by an actual puzzle piece.

Close-up of the sliver dropouts.

This puzzle was commissioned by a customer who said she wanted a difficult puzzle made out of a Georgia O'Keefe flower.