As is par for the course with these updates, there aren't any changelogs included, so what's new is up in the air. The updates are most likely being pushed to fix some bugs and polish up performance however, which is never a bad thing. If version numbers are your thing, you're looking at version 15.820.15120 for Microsoft Photos and version 5.49.2004 for Windows Camera.
Update: As noted in comments, the Photos app for Mobile now has a pivot (swipe left or right) to access Albums and Photos versus the old hamburger menu. A huge and welcome change!
To grab the updates, you can hit up the links to the Windows Store below.