Visual changes are limited in this update to Photos, but there's still some new stuff here worth taking a look at.
A new For You tab is probably the most significant change to the Photos app with iOS 12. The tab along the bottom of the app is where you'll find curated memories from photos and videos, along with sharing suggestions.
The most exciting feature of the For You tab is the sharing suggestion feature.
If you use iCloud Photo library, starting with iOS 12, you will begin to see suggestions of which photos to share with specific contacts. It takes a little time for your device to learn who is in each picture, but you only have to assign a contact to a face in a photo once, and iOS 12 will remember your settings.
When you share photos with people who are also using iOS 12, they will receive a prompt to share photos they have of you from the same location or event.
A more robust search tool will let youtaken at a specific location or event, or with a certain a person. Instead of searching for a single item, you can now use multiple search terms to find a particular photo.