I am a photographer and use the Photos app constantly.
It's really confusing now. I really don't like it. The summary feature only works on albums and the summarized photos are square, which crop the image too much. There should be a square/normal toggle.
Also, when you click on a photo to view it and, if the photo is vertical, there is a rounded corner and the photo doesn't reach the edge of the display, making it smaller than necessary. If the photo is horizontal, the rounded corners are not there and the image reaches the edge of the display.
What are the designers doing?
Slightly disappointed to say the least...