not all of the building is the restaurant "Neue Mensa" although the whole building is called "Neue Mensa"
The restaurant is only in the first/ground level in the middle of the west part of the building (where the note is) and on the outside to the west are additional outdoor seats

there is not one large contiguous space here, but separate ones per building with fences etc.

via StreetComplete 7.1

should not be a building cause it is a more or less open and not really high cooling unit
probably also even less than 1 level high? instead just specify in meters

road outline is wrong

via StreetComplete 6.1