This mural was painted in 2009 by Polish artist Wiktor Malinowski.
It was financed by city of Warsaw and non-governmental organizations.
Words written on the wall literally mean "Stone and what" what sounds like a bit offensive invitation to a discussion about the building, its purpose, history and meaning.
The building was constructed in 19th century. From 1940 till 1942 it was part of Warsaw Ghetto. It was badly damaged due to a bomb explosion during Warsaw Uprising in 1944. It is one of a very few buildings that were standing in a Ghetto and survived. Therefore and due to fights in its interiors during Warsaw Uprising it is treated as the one of a great historical value.