So far, the "importers" have been quite discriminating. I haven't had to decline any photos because they were too small, too blurry, etc. I think everyone's avoiding the bad photos.
Even bad photos can be useful sometimes, however. I might post awful photos of the black spot on my roses or the aphids on a rose bud in the rose forum, and I would never think of adding those photos to the database, but maybe they should be added, with the appropriate caption explaining the reasons for the unsightly look of the photo.