All on iCloud
My shared photos can now be found on iCloud. It isn't the best place to keep them, but it is the easiest.
You can still find photos I've shared with you by opening the Photos app on your iPhone or iPad. If you use an Android phone, follow any links sent to you via email or text to view the photos in your web browser.
Viewing shared photos on iPhone
On an iPhone, open the Photos app and scroll down to shared photos. You may need to click on see all if you have a lot of shared photos to go through.