We were too scared to spend the night. Calling this place "a little bit chaotic" and a "lively neighborhood" is such an understatement that it's close to false advertising. The reason why there are no pictures of the outside of the flat is that, otherwise, you would see how dangerous, unkempt, and dirty the internal courtyard is (and the surrounding streets).
After walking 15min through a dodgy neighborhood, we finally found the place, although nobody was there to open the gate. A friendly neighbor who was exiting opened the door for us, but when we climbed up to the flat the lock box was ripped from the wall.
Not only we didn't feel safe sleeping there (the security bars on the (open) window would be little deterrent to the neighbors from getting in), but knowing that we had to cross that neighborhood at night to get to/from my friend's show was entirely too scary.
We made an effort and spent 130€ on one night in this Airbnb to attend a friend's show during the Milan design week.
The flat in itself looked tidy and clean, and it's absolutely true that we showed up 1 hour before our check-in to be sure we could find the place. The host was also responsive and she tried to understand with the manager what happened to the lock box.
Ultimately it's my fault. I should have known from the euphemistic sentences in the description not to book this place.
I already lost 130€ on this place (no refund) and I didn't have another 150€ to spend on the last min room elsewhere, so we had to go back home = weekend was ruined and lots of money wasted.
I recommend this place only if you have no other alternatives and you know what you're getting into.