Restart your sync using these steps:
- Update to the latest version of iTunes.
- Your connected device appears as an icon in the upper-left corner of the iTunes window. Learn what to do if you don't see the icon.

- Click on the device icon
, then click Photos under Settings on the left side of the iTunes Window.
- Uncheck the box next to Sync Photos.

- When you see a message that says "iTunes will no longer sync photos to the [device]. Do you want to keep or remove photos previously synced to your [device]?", click Keep Photos.
- Click Apply.
- Check the box next to Sync Photos, then click Apply to sync your photos back to your device.