This 15 century treasure is not visible now except through a window . Two many visitors in the past have put it at risk of damage but there is a video ( in German) which gives an extensive account of its history and shows all the paintings in detail .
Beware, when they say you can visit the actual room. You can see the (half lit) room from a glass bubble.
They made a scaled fotographic version where you can watch a film and in between have a look at the picture walls.
I can understand that they want to preserve the room from deterioration, but it should be mentioned...