Enterprise setting. Exchange 2010, Outlook client 2013.
When using Outlook client 2010, this feature worked fine. Outlook is running in cached mode. If I delete the Offline Address Book, the contact photos from the GAL will appear in the preview pane just fine. Once the OAB is downloaded and I restart Outlook client, the photos disappear.
I've seen many other people with this issue but no solution offered. Workaround would be to turn off cached mode but that is not acceptable.