What is a stalking horse? Pretty much what it says on the tin. A horse used by hunters to get close to wild game. Walk on the other side of the horse, the animals being hunted won’t realize humans are in the area until far too late.
Some horses were specifically trained for this method of hunting. The main trick was to get the mount used to the sudden explosion across the saddle when the hunter fires their gun.
(Please click on the picture for the largest version.)
A perfect example, except that the extended range that modern firearms have means that there really aren’t that many horses trained for such work nowadays. It is unlikely that the horse pictured would take a boomstick ringing off across it’s back lightly.
But do not despair, gentle reader, for the continued good health of the fashion model pictured above. Note that the slide of her shotgun is pulled to the rear, the ejection port of the weapon yawning open. The shotgun cannot go off in its present condition. It appears the young woman knows what she is about.
I cannot see the fingers of her right hand, but I would not be surprised if she was not touching the trigger as well.