The frame and picture look good and I can understand folks that do not wish to cut into their drywall to make a "pocket", but IMHO, if you are going to hide a handgun on the wall, the best and proven means is a box in a cutout in the drywall covered by a realistic (not plastic looking) frame and picture.
Having said this.. there are going to be transient workers and renters that will not wish to cut out drywall for fear of the cost of repairs and I can certainly empathize with this. In a home invasion type situation, time is of the essence and fumbling with a closed pouch is a no-no. The OP that said a Kydex holster type arrangement was more on the money, but if your friend's marketing model is for a "universal" type mount, I would probably go with some kind of a solid basket behind the picture so that once the picture is opened/flipped aside, the gun is immediately available along with a spare magazine or high intensity flashlight perhaps (they are SOOOOOOOO cheap on eBay these days. I just bought an 800 lumen flashlight on eBay for $25... and have several 3-400 lumen jobs that cost under $10).
One must always remember that having a firearm close at hand is essential to home defense.... instructions should perhaps include placement of this gizmo. High enough to be out of reach of kids and placed well enough for quick access.
In Canada we must lock up unloaded handguns with trigger locks in Gunvault type safes or big safes (I use both in Canada). The unsafe storage of a firearm is a criminal offense north of the 49th. as a matter of interest.
If your friend wants to get fancy, although the Canadian market is small, the same setup with a metal cabinet as its base and holding an unloaded gun works... with a magazine being carried in the pocket for rapid loading. I know, it is the pits.
US permits bear no weight in Canada BTW, same as Canadian permits bearing no weight in the USA. Carry permits are rare except for trappers up north and politicians.
In fact, the form to apply for same is no longer online.
That is why when we travel, we travel stateside. I have had an attempted home invasion at home here as well as an attempted carjacking in Orlando FL. (A .45 sure does look BIG from the wrong end of the barrel).