I have 622, photos in an album, but when in the photo tab, and albums is selected, I cannot simply make entire album available for offline!
I also cannot enter album and select pictures to be available offline!
I must go and sort through the masses to have offline photos!
This seems like a mainstream scenario: Tons of photos in folders, curate the subset one wants to show others into an Album, take it offline on the phone, show at the next family reunion independently of how ****** the network connection is.
Right now I hack this by having to take a massive folder (say 1000 photos from the last trip) offline so I can show the 'Best of' Album of 100 images so 90% of the storage on my phone is wasted on images I never want to show to anyone.
If there has to be another root offline folder hierarchy under 'Offline Albums' that contains the offline album images (which can be from many different folders of course), so be it - even if there is some theoretical duplication (had the folder containing image A offline AND the album which also had photo A), that's still tons better than what we have now.
Ben Spain commented
This is a big deficiency for the mobile app on Android