Everyone has mentioned right move.
The thing is, for a house of that price bracket, you expect polished, professional presentation of photos and brochure, as well as a tidy, well styled interior. Like another house recently discussed on here, your (reasonable) family things like Ikea bits and office furniture glare out and undermine the quality "brand" of the house. Just move them out of the pictures.
A big one off house needs a floor plan and clear photos titled to match "bedroom 1" "snug" etc.
You have got to give the impression of care and attention to detail or people will think the house is not worth the effort.
The other thing is that any house that isn't the "usual" configuration with a private front garden and larger lawned back garden will take a time to shift. Our village has a few houses like this with a shared drive or other non-standard feature and they have hung around for months if not years, despite being pretty inside. Also there are simply fewer people around looking at that top end of the market and they will be choosy and used to having what they want!