To put it simply, this is a beautiful Airbnb. The pictures represent the house well but, having stayed over a period of 4 days, this is a lovely place for a large group to relax, sunbathe, cook or have fun.
Inside the house, each of the bedrooms have ample space, some storage and air conditioning or a fan, and the bathrooms are considerate with mostly double sinks. The beds are queen sized and comfortable, and there are little touches like free body wash and shampoo etc. that make the house more homely. (one bedroom is a 4 person with singles, at the top of the house, but this has A/C and an ensuite and, if it suits your group, is quite nicely set apart from the other rooms).
There are also 1.5 kitchens, a good mix of nice / functional cutlery and crockery, and 3 distinct eating or relaxing areas. We never felt cramped inside the house with each other, and could split the group up around the house in the mornings or bring everyone together around 1 table when using the BBQ or cooking as a group.
Location is great, the house is quiet from any road noise and its a short walk to the harbour front or into town (Mahón is small, regardless), and there's a Mercado within 5 minutes of walking and the bus station within 15 minutes. There is no beach in Mahón but buses run to Punta Prima, or elsewhere, on an hourly basis and taxis are cheapish.
Sanna, the housekeeper, was easy to communicate with and was very friendly when we met her to pick up the keys. In all, a very nice trip!