I don't class it as 'judging' though, it's assessing and responding logically. It's the same reason that every mini isn't photographed at Golden Demon. People with a critical capacity and understanding of miniature painting and competition pick out entries they predict will do well and photograph them. It's due to time constraints. Here people have picked out the better models and focused more on them.
I'm not directly involved in the process, so can only speculate on the exact criteria they are applying, but as I said before, for me they have picked out all the great entries and really given them the focus that they deserve. Perhaps there are the odd one or two entries in squads that were good and didn't quite get the same amount of images as others as Harry mentioned. but knowing how much work it would have been to do all these images, I am capable to let that go. It's never going to be a perfect process, but this is about as good as I can imagine it to be without a truly titanic amount of work involved.
I would imagine the category the models are in is down to the competitors decision. The photos are good and from looking at your gallery, if those are the photos you are talking about, they are simply not better. Did you look at the magnified versions of the Crystal Brush entries?
You ask how can I know the level of painting on the Warhound. I'm going to be frank about this to illustrate my opinion, and I hope if the entrant sees what I say they understand why I'm commenting on their painting and mean nothing bad from it. It's very clear from what is shown in that one photograph that although the paint job is competent it is totally unspectacular. The photograph isn't a close up, but it shows enough, and is of a good enough quality to see that the finish is fairly basic on every part of the model. I have absolutely no doubt about that. Perhaps it's down to experience, but looking at the models that only have a single image, I can gauge what I think of them and feel confident about that judgement. Believe me, I'm a stickler for photos that show me the standard of the model properly. I feel these do that for the whole lot I voted on.
This is my opinion, and you are totally in your rights to disagree completely, but I am happy I've been given a good impression of the standard of all the entries from these pictures.
I've not voted on biased photos, I've voted on decent photos. Sorry, but that's the simple crux of the matter for me.