Finger sign or no sign, any given personal photo/portrait (this is not a candid snapshot; it is staged/set-up) is at best “move your _______ a little to the _________; now move your _________ ____________, wait, go back just a little to the ___________ . . . and . . . hold it right there . . . good . . . . and ‘click.’ “
Even if it was a purely coincidental and unintended slip that got by the photographer, it would have been caught in the photo proofs and again in the paste up and again in the edits and again in the final edit and then in the cover proofs. Whatever it is, it is not an accident.