Crest releases are regrettably standard in American show hunters and equitation, but taking support from the horse's crest and leaving a little loop or float in the rein are two different things/techniques.
For a hunter, who is not going to execute a tight turn or dramatically change balance or pace immediately upon landing, the release should be as soft and as generous as possible because you want the horse to jump in a relaxed frame, stretched out over the fence with complete freedom of the head and neck. It also demonstrates that the horse doesn't have to be held together or "packaged' in the air by the rider. (A horse that needs that support in the air to jump well, is, de facto, not a good hunter.)
In the photo you used as an example, the horse is jumping in wonderful hunter form with the ideal relaxed but alert hunter attitude. So I'd say the release is mannered, but effective. Of course it would be better if the rider's hand were 3 - 4 inches lower and actually pressed on the horse's neck, but I'm critiquing the execution of the release by saying that, not that there's float or slack in the rein.
Auto releases are more standard in jumping and eventing, where you need the extra bit of control and influence that maintianing contact in the air provides. It is also a more difficult and more sophisticated release for the rider to execute. While I think nothing's prettier than a good hunter being ridden well and "jumping out of hand" ie, ridden with a soft, following auto releases; you won't see that is a US hunter ring any more.
Last edited by maura; 10-30-2011 at 09:54 AM.