I would say the apartment can fit 4 persons, but not for a longer stay as it is quite small and lacks privacy. There are a couple of things that need fixing, one of them being the bathroom door that is touching the ground and makes a horrible noise that would wake everyone up if someone goes to the bathroom at night.
There is another tax of 15 euros for late check-in and late checkout that could be avoided if the host would introduce self chek-in.
Other than this, the location was quite close to the city centre and the host was responsive and helpful.