If some from the batch were reviewed and others left it indicates that there were some potential issues, especially concerning unreleased property, which the reviewer has passed on to a more senior or experienced reviewer.
Fotolia have hierarchy in reviewers?
Do you know more about it? It's interesting. Btw I wish stock sites 'offered' photographers possibility to be a reviewer for a short time. I believe that would be extremely interesting experience. They could offer higher revenue on your own photos for joining such programme.
