It keeps everything in place
I've bought the normal mats many times for other people and have received them from others as gifts, but they move round with wind, door opening, peoples' feet kicking it. This is the first time I've ever bought the tray. I did it to make a more quality gift, and it does two things: Keeps the mat in place and, like a picture frame, it makes the black in the personalized mat pop.
I plan on getting one for myself too.