After his mother gets out of the apartment and witnesses loads of pieces of Western culture... and then the statue of Lenin just flies past her.
The mom starts taking up her former free time work as community consultant (of a sort) from her flat. A neighbour comes, wishing fo help with a letter of complaint about some bed sheets. She dictates the letter, assuming it to be for a GDR ware house. The letter itself is hilarious (very snarky) but it's really topped by the comment of the neighbour after leaving he flat, remarking how she now just has to exchange the adress for the western German warehouse. It's hilarious on it's own - and then you realize how similar western and eastern German mail shopping services actually were in dealing with.