So your hip socket is a little shallow. Hyperextension of the joint allows the ball of the femur to become slightly displaced. This is putting pressure on some nerves. The rub is causing inflammation of the acetabelum. Surgery might be advantageous at some point if the lining (labrum) of the acetabelum tears. In the image (I don't read x[rays) it looks clear that the ball joint is shallow. It also looks (to my inexperienced eye) as though the sacrum is slightly lower on that side which could distort the image.
You might get relief from a chiropractic adjustment of the SI Joint. It could change the imaging of what appears to be a shallow hip socket.
The ball of the joints functions normally within the socket with most activities.
Aside:
I have a labral tear and experience groin pain in the extension of the joint like you. And the same pain after bending. Sometimes the ball gets slightly displaced and can't reseat itself . (I don't think you have that.) Chiropractors can reseat the ball and always adjust the joint between the sacrum and the ilium. It helps but isn't permanent. If you had an x-ray of your joint with the leg raised in the manner you describe, you'd see the ball edging out instead of moving smoothly within the confines of the socket.