Sentence:  "Dori, you have to solve this puzzle!" "Sure, right away doctor. Quality construction... clean edges. Oh, a <WSD>whimsy</WSD>!" 
Meaning of the word marked with <WSD> tags:  A jigsaw puzzle piece that has been cut into a recognizable shape, as if on a whim; often the shape is representative of the theme of the image used for the puzzle.