Hmm... Let me try..
1) Object may be a speculation on the real estate market.
Advertising for real estate, but not selling. Simply to boast the company value.
2) Object is for sale, but the info and photographs are from another object.
They don't want to get thieves around the house.
I have seen this many times on the internet.
3) Get a good advise to buy a house in Belgium. Ask yourself.. Do I want to live in Belgium?
People in Belgium really like their privacy! You meet them in the local bar, not at home!