After the upgrade to the Zou 0.7.8 version we changed the way thumbnails and previews are stored. If you manage your instance yourself and have upgraded it recently, you would have noticed that your pictures were no more available through the API. To fix that you can run a simple command in your production environment:
This command can be very long depending on the number of files you have on your hard drive. So be patient. We added some textual logs to show what is happening. If you have any questions or need assistance feel free to ask in response to this message.