var
lItemIdList: IItemIdList;
lValue: TShellPropertyValue;
lElementType: string;
begin
   lItemIdList := TJamItemIdList.Create('c:image.jpg');
   lValue := lItemIdList.GetPropertyValue(TShellColumns.ElementType);
   lElementType := string(lValue); //TShellPropertyValue is compatible with OleVariant
end;