Just went and tried all the third party widgets mentioned here and they all seem to not do what you’d expect. One opened to the main menu of the app when clicked, instead of showing the photo. Another showed it, but was cropped as a square no matter what. Another one almost worked, but had ads that interferes with the functionality (with no premium version to get rid of them!) The following is the ONLY one I found that gets it right, and it’s free! https://apps.apple.com/us/app/photo-widget-the-best-one/id1532588789