The Photos app for Windows 10 Mobile has been updated for Insiders who are in the Release Preview ring.
The new version adds album creation to the menu system for easier and faster access to enhance discoverability.
The version number for the Photos app has gone up from 16.325.12391.0 to 16.526.11222.0. That matches the Fast Ring version number for the app, and is actually ahead of the public Production version number, which is still at 16.325.12392.0. Presumably, the Production version will be updated soon to match the Release Preview app.