Love the process, but not the final mock-up. While the grey boxes look neat, the visual format is inappropriate for bookmarks. If they use fav icons like the NY Times logo, you won't be ale to tell what the bookmark is about. Small screenshots of the pages also don't work since they become illegible and many times only ads can be recognized since they are made to stand out. So this concept should be validated with real content. I'd assume that a text-based version would be much more usable.

I'm looking forward to see what will come from this.