It could just be a wallet reskin, but an alternative that would be a bit more work (but cool) could be a reskin of a display case with a chyen-only flag. Thus having a integration message that showed how much chyen was stuffed inside.
If it allowed for more chyen storage than a wallet this could arguably be a gameplay benefit because it could slightly encourage keeping more chyen in vulnerable and visible locations.
I would also make it impossible to 'stash'. If you carry it, it mush be in hand where others can see it. I'd even love it if it was given priorities in the automated shortdesc so that 'hooded average chum carrying a chyen jar' is very likely. Then looking might show they have a cheyn jar with a 'who lot of chyen' in it. This would be to disincentivize characters from using it as a wallet replacement.
I agree with 0x1mm in that it could create RP. A slightly more blatant temptation for those you bring into your hope to rob you or leak word about how flush you are to the right people.
Drinks/barrels/cans: Nearly empty, quarter full of chyen, etc.
Containers: A pile of chyen.
Pay: Some chyen, a shitload of chyen, etc.
Count/Wallets: XX,XXXc.
Batteries: [##########…]
The ones that seem to make the most sense to me are wallet or pay values, only because the drink code on high capacity containers tends to always show nearly empty, but really any of them would be awesome and I think this idea in general is super cool.