I have mapped the picture (thumbnailphotoattribute) to a column, but the picture does not show after synchronization.
Please check the settings below:
1. The pictures will be attached to list items during synchronization, you must to enable Attachment feature in the list.
2. If you have mapped thumbnailphoto to a Hyperlink or Picture column, make sure the Format URL as option is set to Picture.
Applies for: SharePoint 2013, SharePoint 2010, SharePoint 2007