We rounded up our 2016 milestones. Check them out here.
Fix the paths. What's the difference between img/completed-projects & img/project
If there's a difference, make a clear distinction. And don't mix the two.
If there's no difference, consolidate.
Also, make sure to remove all unused images.
If a/b/c are grouped by some factor (size?) include that in the filenames to make that clear