This seems to be a common decoration as nearly every grocery store in my town except Savemart seems to have one of these. There is one other store I have not yet looked at, but I rarely go to that one. I may just do so just to see if they have one of these displays.
This one (above) was taken at Nob Hill and looks a lot like the one I took last week(at right) I looked closely at this display and saw tape on the boxes. I then carefully touched one of the boxes and could tell that it was empty, something I should have suspected all along. I wondered how they could have balanced all these boxes this way, but I should have known the boxes are empty. There is no way they could have balanced all those boxes if they were full. And look at how the "stems" made from Mountain Dew packs are constructed.
Notice in the photo above the cutouts and the "Be Scary" sign.