Are there any digital photo frames that support WiFi and enable my family to send photos for automatic display on the frame? Many options are available, typically with a resolution of 1280x800, which might be acceptable. I suspect the differences lie mainly in the quality of the proprietary software they use.
Purchase a smart display from Lenovo or Google, then set it up as a shared Google Photos album for the screen saver.
You can apply the same method there as well if you subsequently give them a Chrome cast Chrome OS device.
@Zendaya I acted in this way because it was the best course of action for my parents and me. For 50 euros, you can get a Google Nest Hub, which is reasonably priced and offers more features than your average picture frame. My mother uses it as a timer and loves to watch YouTube videos on it while cooking.
My stepmother is a fan of her skylight. Although I find email photo sharing a little awkward, it functions and she knows how to ask others to send her pictures. It also offers a somewhat less complicated phone app, albeit it would be more difficult for her friends to understand.
For the best image quality, the Aura Mason Luxe frame is the digital photo frame to get. Its high resolution display is outstanding; colors look realistic and the detail is precise. The swipe interface makes it easy to use too. The Nixplay Touch Smart frame features a touch screen which lets you navigate seamlessly.