Loads of photos over on Google Photos. Head over to https://photos.google.com and look at what has been shared with you.
Not sure how to do that?
Open https://photos.google.com in a web browser, click on the menu bar icon top-left to reveal the menu and just head to Sharing. Anything shared with you will be in here.
If you’re using Google Photos on mobile, then the Sharing button is the one on the far right at the bottom.