I also found this mini version of a jam cabinet in a different barn:
I actually think it is meant to be a box with a hinged lid, since there are handles carved on the "top" and "bottom" (being on either side of the lid). Maybe it was some kind of tool, or ammunition box; since there is also half of a hasp on it for locking it with a padlock. But I turned it up on end as, as you can see.
That is the original shabby paint. It takes care of that big, empty, useless corner of the kitchen cabinets very nicely, with the addition of various kitchen items like jars and such.
Whatever it's original use, it's found a new life now!