By far the majority of the supposed 'subliminal' images allegedly appearing in JW literature are well within the realms of pareidolia. That is, there isn't really anything special about the image, and the thing people are supposedly 'meant' to see generally isn't at all 'apparent' until 'revealed' by a big red arrow, outline or box along with a detailed description of what the person is 'meant to see', sometimes with instructions to rotate or fold the image to 'reveal' the 'subliminal' image.
In other cases, an image might be deliberately modified by an artist who is 'rebellious' or simply bored. There is no evidence at all that any artist (or any other person) has ever done anything because they were 'demonised'.
In this particular instance, I think the image you're referring to was actually in Revelation—Its Grand Climax at Hand and not You Can Live Forever in Paradise on Earth. The image is sometimes touted by over-excited propagandists as a 'lobster claw', but the discoloured hand quite definitely has four visible fingers and does not remotely resemble any part of a lobster. The most likely scenario in this case is that the artist was simply having some fun, though it is not impossible that there was subsequent discoloration of that part of the image between the original drawing and production of the printing plates.
Additionally, 'subliminal' images cannot have any effect on someone who is not already familiar with what the alleged 'subliminal image' is 'meant' to convey. For example, if an image surreptitiously contains some symbol that was worshiped by a tribe of extinct midgets, the 'hidden' image has precisely zero effect ('subliminal' or otherwise) on a reader not familiar with the symbolism (and no supernatural effect on someone who is familar with the symbol).
