Your apps recognition ability is atrocious. Doesnt catch exact duplicates I saved to test it. Given recognition software has been around for years why is it failing to do what it was "designed" to do? Im being generous when I say it maybe manages to find 1 duplicate out of 50 photos, the rest have no discernible similarity. Whoever the programmers are should find a new occupation. If this is the best AVG has to offer, close your doors and find a new line of work.
Talmak427 about AVG Photo Cleaner and Manager, v1.3.3