I have a Google Photos album (shared with a few close family members) that automatically adds photos of my daughter and syncs them with the Aura frames her grandparents have. We've had this setup for the last two years and it works really well. I think it's literally the use-case Aura is targeting.
I don’t use Google any more but it looks like they have the same functionality for iCloud. I’ll have to give that a try since it’d be perfect for our older relatives.