The head is too low.
Here are the AQHA rules regarding head carriage;
453. WESTERN RIDING
Western Riding is an event where the horse is judged on
Quality of gaits, lead changes at the lope, response to the rider, manners
And disposition. The horse should perform with reasonable
speed, and be sensible, well-mannered, free and easy moving.
Credit shall be given for and emphasis placed on smoothness,
Even cadence of gaits (i.e., starting and finishing pattern with the same
Cadence), and the horse’s ability to change leads precisely, easily and
Simultaneously both hind and front at the center point between markers.
In order to have balance, with quality lead changes, the horse’s
head and neck should be in a relaxed, natural position, with his poll
level with or slightly above the level of the withers. He should not
Carry his head behind the vertical, giving the appearance of
Intimidation, or be excessively nosed out, giving a resistant
Appearance.The horse should have a relaxed head carriage
Showing response to the rider’s hands, with a moderate flexion at the
Poll. Horses may be ridden with light contact or on a reasonably loose
Rein. The horse should cross the log both at the jog and the lope without
Breaking gait or radically changing stride.
The judge will select one of the four patterns to be performed.
The judge is responsible for the pattern being correctly set.