Unable to answer "This shop has been vacant. What’s here now?" – Möbelina – https://osm.org/node/9657766052 via StreetComplete 59.1:

Children's book reading space. No advertised opening hours.

Attached photo(s):
https://westnordost.de/p/243496.jpg
https://westnordost.de/p/243497.jpg
https://westnordost.de/p/243498.jpg