one of my favorite kinds of shadows are the mysterious ones that are virtually impossible to guess. while virtually each and every shadow is unique that does not necessarily make them mysterious. there are a number of reasons why a shadow can be so enigmatic. one of them is the lack of depth. for example consider a situation where two separate items are casting converging shadows onto a surface and it is not possible to see the items themselves only the shadow. usually there is no indication of which section of the total shadow belong to which image. if the items have no connection other than they happen to be positioned near each other then the shadow created by the combination can be most perplexing indeed. like here for example. before reading farther try to imagine what is creating this shadow. here's a hint: there are two everyday items that are regularly placed near each other creating the main image. a third and fourth item adds some detail. the sun just happens to be shining through the window at exactly the right angle to create this odd combination of shadows.
solution below
a steel plate on our wooden dining table with a carved rosewood chair. a plastic bag on the table casts its shadow on the plate, a little on the carved wood and as seen in the first shot a little on the wall adds the minor detail. i didn't create this shadow deliberately. i just happened to observe it. now it's possible you may not have steel plates and carved chairs handy but imagine the possibilities of creating unusual shadow images so simply or even so unintentionally.
happy hunting