I can only agree with the previous reviewer: Céline was a nice welcoming host but for the rest the flat doesn’t look, feel nor smell clean.
Of course this all depends on personal standards (I admit mine are quite high) and also for this price you cannot expect too much in Paris but still more effort could be made, e.g. get rid of the (humidity?) stains on the walls and add some paint or wallpaper, put the cat litter somewhere else than in the tiny bathroom etc. etc.