Although there are many different types of standing posture, there is no one 'ideal' or 'correct' posture. Many people may have unusual or 'abnormal' postures as the picture above, yet develop no direct symptoms or dysfunction as a direct result of this.
Neutral posture: The red line above (or plumb line) in the sagittal view should pass through the lobe of the ear, the shoulder joint, the hip joint, though the greater trochanter of the femur, then slightly anterior to the midline of the knee joint and lastly anterior to the lateral malleolus.
Look for lateral shifts or a list
Gaps between arms can give this away
A Scoliosis
Hand height