To be honest I cannot see anything obviously wrong. Truth is the camera just doesn't do justice to seeing what you are seeing, and I'm no trained professional either. Another possibility is that birds conceal their problems well, as it is in self-defense of predators, because they pick off the small and weak. Lastly, birds could simply be asymptomatic, meaning they carry an illness but show no signs of it. You, I, and anyone else untrained in avian medicine or at least a vet could simply just keep guessing at it all day long. It's why everyone keeps telling you to see a vet. They can run tests, see things we cannot, and provide treatment if necessary and available. Thing is, if something is wrong and you or anyone unknowingly for sure do a self-diagnosis and then try and treat what you guessed it might be could actually do more harm, if not become fatal to the bird. Best leave it to the professionals.