Sorry, in the particular case of your pictures the problem is episodes. Castle has 1500 stills and I'll have to find the episode they belong if I don't want to have a mess of pictures for a series (imagine if they were all that way). Of course it it was just quality and duplicate comparisson it wouldn't take that long, but some users don't tag, some miss to include season/episode, and some users both at the same time... and I'm sorry but that takes time, having and organized database of stills takes time.
Also, at the moment I can't easily think of moderators that could be included to the team that are willing to take the necessary care to the organization tagging and looking for episodes, so were are very few doing it.
Again sorry because the fact is you took the time to tag and at least put season and you're a user that usually have easy to approve uploads where I only have to look quality and duplicates.