

Any electronic device with firmware in flash. The charges will have decayed a long time ago, leaving a paperweight.
Sufficiently diligent far-future archaeologists may dissect and catalogue the devices well enough to develop a taxonomy of components, having their own names for components, CPU architectures and such, but they’d then be left with something like “this was a programmed control device of the Xargx Valley type, variant 13, only with a screen, a speaker, two microphones and a motor actuator. We speculate it may have been a domestic appliance, a children’s toy or part of a transportation device. Alternatively, it may have had religious or ceremonial uses.”
PostNord is not state-run: it’s privatised, and operates mail for both Denmark and Sweden.