Not that it really makes a difference, but I believe the win is in the pin, not the room or the spot you are standing in. I use all of my pins for all of my characters in my dark unfurnished room and walk from one end to the other and back each time. I have won quite a few buried pins, tiki fountains, sorcerer hats and lots and lots of credits.
Because I win the prizes in my own room, I believe it to be the pin that determins the prize, like maybe a programmed cycle of which prize is given out in order based on use. Hope that makes sense.