OK so here's the deal with the whole "pictures are gone / missing after iPhone screen replacement" situation.
It's nothing that the techs are doing so far as I can tell to date. I'd love to know what is causing this so if anyone has a theory, please chime in.
Now, with that said, we had never had this issue before after well over 3,500 repairs. Until recently. We've had this happen to 2 phones in the last few weeks. And believe me, we are professionals, so I don't know what to make of it.
But here's the good news. The customers (or your) photos are still there. It's just that the camera roll preferences are trashed or screwed up. Here's how we know.
As mentioned above, Funbox is a solution. But we bypassed that because we use Phoneview for our data retrieval. Or iExplorer. I think you have to pay for both, but anyway........ when we plugged the customers iPhone into Phoneview, all of his pictures were there. So until we can find a cause for this issue in the community, you will need to use one of the 3 above mentioned programs and backup / copy / extract all of those photos to a safe place (like into a folder on your desktop), then re-synch them back to your iPhone.
Yes a pain, but hey, you just got your pictures back, no?
On another note, why not just restore from iCloud backup? Oh, you don't have any backups? **SLAP!**
Learn this lesson now and go turn on iCloud backups over WiFi in Settings>iCloud>Backup and Restore. Now! Because if you had last nights backup, we wouldn't even be discussing this right now.
Hope this helps, and please, CONTRIBUTE YOUR FINDINGS about this issue.
P.S. DO NOT FOLLOW THE INSTRUCTIONS IN THE POST BELOW BY IVY. NOT ADVISED AT ALL.