Yes, Nuno is an extremely pleasant host. And yes, the room in the ad is the room where you can stay but not you alone. It is a room that you share with Nuno and the other guests. My own room was a very basic decorated bedroom of approximately three by three meters with a view of a nearly blank wall.
There is a well-equipped bathroom and kitchen but also to share with the other guests and Nuno, there is nothing wrong with that in itself, but the ad suggests otherwise. It seems to me, therefore, useful in order to adjust it. Finally, the view from the beautiful room is gorgeous but that comes after climbing 64 steps. But if you do not like climbing you have a problem throughout Lisbon.