I noticed that, too. Also, Louis crossing the second and third fingers of his hand in a really unnatural way. If you cross your fingers, you don't cross those fingers, and not in that almost impossible way.
I'm honestly not a conspiracy theorist. But I do know the press pretty well and believe that it is on balance a pretty big thing for the biggest photograph news agencies to issue a kill notice - particularly one of a very high ranking royal, taken by the heir to the throne.
Either KP asked for the photo to be withdrawn due to Kate not wearing her wedding ring (for whatever reason, whether sinister or not), or the press are signalling a complete lack of trust in what they're being told by the Firm. The Royals are powerful, the media is more powerful. Experience tells me that there is generally no smoke without fire where the press is concerned.
I've also noticed that the BBC version of the photo has now been cropped so no hands are showing. The earlier photo showed Kate and the children in full. The BBC will be heavily dictated to about Royal protocols and in the hands of the Royals, as we saw when newsreaders donned black several hours before the announcement came about the Queen having died.