Yes, Margo, you are right that the legs are wrong in the photo
but, the correct posture is not exactly vertical hocks, but only near to vertical. The line that joins the hock joint and the point of ischium should be vertical in correct posture, but the paws of the hind legs are slightly to the front, so the back of the paws can touch the line, not the middle of the paws. The dogs which stand with their hocks vertical to the ground usually have the paws and hock joint positioned behind the point of ischium, or the posture is too steep (or how it is called).