Placing beds/furniture into empty rooms definitely helps provide an idea of scale. Generally empty rooms look smaller than when they contain even just one basic item of furniture. The next trick of course is to buy small furniture, and don’t place it next to the wall. In the above photos they’ve done the right thing in using what appears to be a small 2 seat sofa, but they should have moved it slightly away from the wall and placed another one either facing it or at right angles. Therefore potential buyers immediately see (and more importantly remember) that the room can easily accommodate 2 sofas and a dining table. All items must be neutral (as in the photograph) so they give ideas regarding the basic layout of the room, and its potential, but leave it to the buyer’s imagination as to how it will ultimately be decorated (they might be minimalists after all!). The room in the photo doesn’t really need much else anyway because it has windows on 3 walls and plenty of natural light.
In the UK especially there is another advantage in including a bit of furniture – it gives the buyer the option of offering say 10k less for the property in order to bring the price below a tax threshold, and then they can offer 10k for the furniture instead. Perhaps not the most honest way of going about things, but entirely legal, and it’s what many people do.