The apartment is exactly as it is shown on the pictures. There is an elevator for visitors who have difficulty going up 4 flights of stairs or for those with big luggage. There is air-conditioning which was really nice considering we visited Lisbon during the heat wave. The apartment is extremely well located with the station/tram stop less than a minute away. The only hiccup we had was with the self check-in. It was particularly troublesome considering we arrived around 3 am in the morning. However, with the help of our kind and willing driver, we managed to contact the helpline and eventually made it in.
Added perk: There is the well know bakery right down the street for a quick early morning coffee (make sure to try the croissant brioche!).