Well done putting your apartment on Airbnb, Vasilis! You have obviously taken the trouble to make it look attractive.
At the top it says accommodates 3, and further down it says 3 guests, so it looks as though you have done that all right.
It's in a great central location so you might want to say how far it is to the nearby Acropolis and the National Archaeological Museum.
When you have time, you could put a photo of the kitchen and bathroom. I see you have a pretty balcony; people love that, so you could get a photo of it and the views from it. A photo of the outside of the building is another idea.
It isn't clear whether the 'second bedroom' with the sofa bed is also the sitting room - you could label the photos.
Good luck with your bookings now it's the holiday season!