iCloud restore blank photos

Had to take daughters iPhone 5 in for the lock button repair, backed up to iCloud beige handing in and restoring.

Got a loaner and restored from iCloud fine, got original repaired iPhone back and restored. However in the camera roll there are loads of photos with a blank square ie there should be photo there but it's missing.

Anyone help as daughter is going mad, don't back upto iMac now as just use iCloud.

Thanks