Yes, it looked similar to the picture of the cathedral. I just about fell over when I saw it, I've never seen a bit like that. Would this be a bit that you would use only for shows? Kind of seems like riding with a constant threat over your horse.
I believe that the original use was for incredibly light cues that not only cue at the bars, under the chin, and on the poll but also on the roof of the mouth. Just a design to give the horse one more thing to feel. You have to ride your horse with very soft hands in one of these because they can really cause a horse to gape their mouth if you take a hold of them even a little bit.
Also, I am not sure that horses have gag reflexes but considering a horses mouth is almost a foot long, I really don't think they need to worry about choking on it. LOL.
Those bits are great for WP horses. When you have a loose rein, advanced horse, and soft hands it makes it easier for you to do barely anything and not be noticed by the judge when you are correcting your horse. I wouldn't use it on my pleasure horse since he has a sensitive mouth and neither him nor I are ready for a bit like that but the ones who are get great effects with it.