Just throwing out a guess here, but maybe the items in the backpack in the video blog all pertain to each specific house. The first being shown to us directly is a cell phone with a video clip of a cabin in the woods on it. Hence the first house revealed is The Cabin in the Woods. Although we only see them pull out 3 objects before the cell phone, there could be more inside of the bag yet to come. I think it would be a way to link the houses together without a direct tie in to each other.