From their page, "The app can also help you quickly enhance photos and combine them in new ways to help you relive your life’s moments. In one tap, get instant adjustments tuned to the photo’s color, lighting, and subject to make each photo look its best. Press the “+” button to create your own collages, animations, movies with soundtracks, and more.
If you swipe to the left, you’ll open the Assistant view, where we’ll suggest new things made with your photos and videos, such as a collage or a story based on a recent trip you took. After previewing the creation, you can choose to keep, edit, or discard it."
See...that is the kind of sharing that people really want to be able to do with photos much of the time. This will probably be very popular for people who want to be able to share images. Of course, that's not for everybody (like photo forum people), but only for the majority of people on the planet. You can bet that this is another attempt to embed a Google service into popular culture, as a way to later leverage it.