The problem with the theory is how it would have to work in practice. I can't figure it out based on my own experience working with brothers in Writing, brothers and sisters in the Art Dept, and brothers and sisters who photographed and prepared the artwork for printing.
1. One of the writers in the Writing Dept is asked to write an article (or a special assembly talk, etc.) which may eventually become an article or included in a publication. (Are all the writers supposed to be in on the "secret" or just a few -- or just one? Is there some member or members of the GB who are in on the secret? I think most people would be surprised at how little the GB are involved in the Writing Dept or in the writing process.)
2. The original article is printed out with the initials of the writer and at least one set of initials from the "approver(s)" in the Writing Committee. By the time the Art Dept gets it it has usually already been proofread, and may have even cycled back to the writer at least once, the proofreader's initials are also there, sometimes with a few brief marks or questions. If the artwork is going to be substantial, or if it needs to run in the next issue or ASAP, then rarely, the Art Dept may get a draft or early version of the article. The artist is also expected to read the article carefully to offer appropriate ideas. I always had to give 2 ideas, sometimes 3, before being allowed to really start. (Since everyone in the Art Dept can easily figure out who is responsible for the original article, and all the approval initials along the way -- and they also know which artist is working on every piece of artwork, any conspiracy would break wide open unless everyone in the Art Dept was in on it. That would have to include new brothers and sisters just starting in the Dept. This is one of the reasons I consider this to be silliness, because it would have included me and every person I knew in the Art Dept from 1976-1980, and even people that I still know there in the Dept.)
3. Artists almost never speak to the writer directly. Although sometimes the writer might want to speak with the artist directly, it was almost never initiated in the other direction, except through overseers. In fact, even though we all recognized the initials, it was kind of an unwritten rule that we pretended we didn't know who wrote what. It was considered bad manners to be so indiscreet as to say anything that showed we could identify the writer. People worked openly, near each other, not locked up in their own room. It was always possible to see what someone else was working on. (This climate would have made it very noticeable if a GB member, an Art Dept overseer, or a writer himself needed to converse covertly with an artist.)
4. When the artwork was finished it was sent over to the 8th floor of the factory at 117 Adams where it was given to "Photoplate" to be photographed. Photoplate also served as an auxiliary Art Dept when the artists in 124 needed some help. It was also where a lot of the simpler "graphic arts," special headline typesetting, stat photography, and other technical support for the artists actually took place. (Also, this was where some artwork was reversioned slightly for some of the foreign issues of the magazines.) Color artwork was shot (with various combinations of color filters) on the camera for each color printing plate that was used. We were just moving to 4-color and offset in those days and had a lot of trouble getting rid of the very kinds of printing anomalies that people see as subliminal images. Getting rid of "accidental" objects and discolorations or "drop-outs" or "fill-ins" or images that looked like faces often took a lot of extra shots and camera settings.
This is where the real trouble would have been for anything that was supposed to show up subtly, because a slight change of dot size or "screen angle" or inking issues might have made a subtle image way too overt, or make it disappear. In truth we did often try subtle stuff, but we often had trouble. By subtle I mean things like trying to get steam to look realistic coming out of a cup a cup of coffee, or smoke from a factory or cigarette. Even clouds could look like rocks if the process wasn't watched carefully at every step. So now the biggest trouble with subliminal images is getting past Brother Bill Gehrig, Brother Robinson, or Sister Judy Martin looking at the last negative under a magnifying glass to ink out dozens of tiny, extra spots before the art made it to the printing plate. Then you'd expect them to have to let each of the foreign edition printers know about it, so they can also be careful not to ruin the subliminals. (Some foreign editions need to manipulate the artwork to fit longer or shorter titles, captions, or run text right through a lighter version of the artwork, or they need to reduce the size of artwork or cut out some artwork altogether to fit the text on fewer pages, or for monthly vs. semimonthly, etc. etc.) I mention names just as a reminder that there are lots of real people who would have to be just as involved in a conspiracy, or even more so, to finally get those subliminal images on paper. Yet these people, if you knew them, were hardly "loyal" to WT policy in every sense of the word.
5. And there were many more poeple-- film developers, offset platemakers, people running the initial paper press proofs, the factory proofreaders who had to see final typeset page in context with artwork. Then it finally got to people like Tom Cabeen, Randy Watters and at least a dozen more folks in the pressroom who would have to make sure those subtle pictures were coming out OK. Tom was running the pressroom; he was in charge of the printing from the metallic imaging processes AND then the offset imaging processes. He would have to have been a key player in the subliminal images conspiracy. Yet Tom is a very serious yet outspoken ex-JW (and friend of mine). Why doesn't Tom know anything about them? Randy Watters had a lot of responsibilities in the pressroom along with Tom. Randy runs a huge exJW website, freeminds.org which plays the subject down except for showing one or two pictures claimed by someone else, but without personal comment by Randy. (Randy does let Derek Barefoot sell his book on the site, so I can't say I know exactly what Randy thinks about it.)
If you are a JW, by all means be offended and leave the JWs over any reason you can find, but please make it something a little more substantial than subliminal images!
Just my opinion,
Gamaliel