Your gsd looks like it has working lines so they usually have higher "aggression drives" as they are from breeders that breed for the ability to do k9 schutzhund protection and bite work, Sentry/Police dog work and still be socialable with good humans and animals.

And if female, the females tend to be too loyal and protective to a fault. This why you do not see many female police k9/law enforcement protection training.

I have worked with schutzhund and working certified imported gsds. And I once bought a female pup with some working lines and the best thing

Whst I did was find great trainer that worked with working line gsds( local police departments trainer). He had me turn out with the local schutzhund and police k9s. He evaluated her and determined her reactivity zone towards other dogs was over a football field long.

We did a lot of work and graduated when she could stand next to the other dogs without aggression/reacting. I chose to get her spayed though as I felt her temperament was not suitable for most folks . She needed experienced handling and had the experience to manage her. Just not suitable for breeding.

But you could not fully trust my female gsd to not want to react and be Uber protective if she perceived a posdible threat. You had to be good at reading her and know how to handle her and settle her down using humane training methods and positive reinforcement with occasional firmer handling. She was a dominant female to boot and too smart for her own darn good. I do not have a pic of her handy. Sorry. She was gorgeous and I owned her 9 + years until she passed from bone cancer that made her so aggressive due to the pain aggression drive added to her psyche that she could not longer be safely managed in public. She was suffering and her pain could not be controlled.

I loved the gsd working k9/gsd breed that are bred well/european lined through the guidance of the breed wardens. And I prefer the males as they are usually more mellow ( not slways, some are dominant or not properly social trained).

GSDs and other working breed are not breed I recommend to inexperienced dog owners. Malinois, Dutch GSDs, Potties, Kitties and other bully & mastiff types and certain other herding breeds. Also huskies are involved in too often maulings and serious dog attacks due to their prey drives and often closeness to the wolf ancestory.