What I said about the 5% was an example and my opinion. It was in no way a criteria. I think pictures should be representatives of the series (Manga/Anime/Zero), and so proportionally consistent. Nevertheless, with the addition of fanart (which in itself is not much), I can understand this might be the best criteria.
Now, as to the amount of pics, I see many pictures of the same scene (as if attempting to rebuild the movie frame by frame). This I think we could minimize. One or two pics of each scene. By using this criteria, maybe the number of pics in question here could be reduced, but it would also affect other pics as well. I don't know.
At the end of the day, until a clear criteria is set, if there is any particular picture we really think shouldn't be here, like Dig87 just said, bring it to our attention and we can discuss accordingly.