I also disabled Peel Remote yesterday. Since rhen the mysterious notification did not appear anymore.
Not really a solution but at least a workaround. For sure this is a disturbing behavior of an app.
Related search results:
https://forums.androidcentral.com/ask-question/792965-why-does-pwbg-jpeg-appears-my-phone.html
https://www.reddit.com/r/googlephotos/comments/69p24g/mysterious_photo_randomly_appeared_in_friends/