I don't think it is for concealment...
It is short for rapid presentation. I think it is marketed as a "backpacker's friend."
"Alaskan" guns are a big rave right now. Supermagnums with barrels under 4". You can shoulder-carry, strong side carry, cross-draw carry, whatever, and it has several inches less to draw and present to that nasty growly thing 10 feet away and closing.
The only problem is the recoil of the .454 or .460 and re-aquiring target for a second or third shot because you missed on the first one while the target is 10 feet away.
I do worry a bit if some gang-banger decided to carry one of these concealed with .460 ammo in it to defeat LEO body armor. I think that .454/.460/.500 will defeat level 2 armor, but I am certainly not an expert.
God help us all if that happens and Nancy Pelosi decides to exploit it to ban supermagnum hunting pistols.