I don't mind the blurry pictures at all. What bugs me is that they're eventually replaced with detailed pictures that don't add anything that the blurred pictures weren't providing already.
That process could probably be automated. Run a big collection of clip art through an image classifier to get keywords, and just load some image with relevant keywords. Good Wordpress plugin to write, if someone hasn't done it already.
So they load an entirely different image first? Why not just (re-)encode the image with interlacing[1] turned on?