As a pp said, there’s a difference between ‘noticing’ and ‘looking for’, plus I think answers to this question, which comes up a lot of Mn, are often distorted by people who confuse a house sale with an interior decor or Housewife of the Year competition.
I will absolutely notice the smell, for instance, but what I’m looking for is size, location, layout, aspect etc. I’m thinking ‘Can this house be made to work for us?’ in conjunction with how much work I’m prepared to do, and, obviously, how long we plan to stay. Our current house was a former student house, in an appalling condition, in a huge garden of waist-high weeds and stank of dog, for instance. But it had beautiful, plain bones, was in a great location, and was so obviously going to repay the work.
No one has ever failed to offer on a house because someone left out their dandruff shampoo on the bathroom counter, or an oven glove on the cooker door. That’s just silly.
A minority of Mners say ‘Ah, but knickers on the floor indicates a fundamental lack of concern which may translate into the house having been neglected for years!’ like it’s some kind of ‘gotcha’, but I don’t think there’s any correlation. Not in my experience, and I’ve bought and sold houses and flats in three countries. (And have never done more than give the place a good clean and retouched scuffed paint. Selling an ordinary house in an ordinary market doesn’t need to involve elaborate ‘staging’.)
But I’m more than happy for other people to make decisions based on completely mad criteria, like toilet seats up in photos. It leaves the rest of us who can see past toilet seats and family photos more options.