[verygoodname]

As it is explained in the "readme" part, in this specific context, "naturally occurring" means that no one has purposefully manipulated any of the images to make them collide: that the images were already published and "out there" and happen to collide. In other words, it does not necessarily imply that the images correspond to natural photographic scenes (which seems to be your interpretation of it).

Besides, you could probably "naturally" obtain such type of colliding images by photographing similar-looking objects against a white (or generally featureless) background. Furthermore, it suggests/demonstrates that similar-looking images with similar backgrounds can lead to unexpected collisions in practice (i.e. "naturally"), even if you do not assume an adversarial scenario.

Are you sure that, if you take a picture of a naked body part, it won't collide with anything that looks similar in their database?

[nextlevelwizard]

It is unlikely unless you manage to capture some position and happen to have some background. This whole thing is a nothingburger. This is one of those weird things were many people have baseless gut reactions and then try to go and prove if flawed even though they don't have a complete picture.

It is unlikely that there is a collision of benign image with the database and even if that happens it is not some automatic process that just sends cops to your house to raid it.

Of course we can get bunch of collitions with essentially same images, I don't get why this is so magical just squint your eyes and I'm sure you have two objects with in your reach that could be made to collide, but that isn't a gotcha on any level