Photos app doesn't show any photos when Internet connectivity is limited
Even thought the photos are stored locally, when in the main view of the photos app only the thumbnails or nothing at all (if thumbs are not cached) will be shown when internet is off/blocked/limited.

The only way you can access the local copies while using the photos app is to open the menu on the left and select "Device Folders" and then go into the Camera folder (or wherever it is you are trying to access).

Click Images to enlarge





Unfortunately because the internet is limited you wont have access to the nice new features such as the advanced photo search or the nice date order layout as these are all server-based features.