It could be many situations including looting,,,,,,,,,,,,,, spoils of war,,,,,,,,,,,,,,,,,,,,, trading with sympathetic or un-sympathetic locals,,,,,,,,,,,,,,,, evacuation of friendlies who took over shops in occupied areas,,,,,,,,,,,,, or even helping them into the shop - you tell the story and you have the models as the props.
If it were occupation or evacuation of friendlies who took over the shop you could have some subtle vandalism such as nazi propoganda or free French or Orange (Holland) graffiti on windows, walls or doors.
Lots of options
Looking forward to the story line
Nige