Have a column in a SharePoint 2010 list set to Person or Group. Name (with Picture)
The property or field has not been initialized. It has not been requested or the request has not been executed. It may need to be explicitly requested.
I am loading Photo column explicitly:
clientContext.load(collListItemBlog,'Include(Photo)'); // //later alert (oListItem.get_item('Photo').get_lookupValue()); // prints name alert (oListItem.get_item('Photo').get_url()); // errors