The penalty box is used for hockey games when players get penalties. Since the players are carrying sticks/are all bulky someone needs to open the door for them. I don't really understand all the intricacies and consistently messed it up the first game I did it, which was also maybe the second hockey game I'd ever seen live. My roommate plays for (and founded!) the women's hockey team here, so me and all of our friends do the announcing and various admin jobs.