That's great news on the screensaver, thank you for your continued development belltown!
I admit it's a bit confusing sorting out the photos/videos available across Google's product set (Picasa Web Albums, Google Photos, Google Drive, Hangouts, etc).
Google Drive has a "Google Photos" folder/tab (sometimes auto-sorted in folders by year), but any file/folder organization there is not reflected in the view at the actual Google Photos site/app. Likewise any albums, photo edits, or the auto animations/collages/etc at Google Photos don't show up in the Google Drive view.
As far as Picasa Web Albums (both on the site and apps), it shows "Auto Backup" as well as any manual albums created at Google Photos (it also seems to show pictures sent/received from Google Hangouts sessions).
On the Picasa Web site, the "Auto Backup" album is organized into a separate sub-album for each day, and the deprecated "Instant Upload" album (which is empty most of the time) still shows up for some reason. But on the Picasa Roku channel, "Auto Backup" plays as one slideshow without sub-albums (more practical?), and there's no "Instant Upload".