Hi,
Use the app provided by Dlink for your iOs system: Mydlink NAS Acess, it allows the syncronization of your default camera photos in the iphone directly to your NAS. I use it here in Android and it works OK, via WiFi or via 3G/4G.
Second, the iTunes server provided by the Dlink NAS mentioned (DNS 327L) only acess and list your musics, not movie files.
Regards.