I wonder if someone is confusing two different events??? Sometimes a roll call group will organize a Gift Exchange in conjunction with the Meet & Mingle. People who want to participate bring a gift that represents their state or city. There's usually a price limit and some kind of agreed upon process (like Dirty Santa) for drawing names or numbers to exchange the gifts. And sometimes people will voluntarily bring something to be donated as a door prize at the Meet & Mingle. Usually there's a Royal Caribbean rep there with some RC swag for door prizes, and whatever people bring gets added to that and given away by drawing ticket stubs.
Cabin Crawls are different. It's like going to a bunch of real estate open houses during a designated time period. People volunteer to "open" their cabins for viewing, and those who want to see different types of cabins walk around the ship to view them.
We've participated in many Cabin Crawls, both as a host and as participants, but none of them have really involved gifts. I've seen a candy bowl in a cabin before. Also a cookie tray. On one Mardi Gras cruise years ago, a pair of ladies handed out mardi gras beads in their cabin, but that was more like a party favor.
If you volunteer to "host" your cabin for the Cabin Crawl, you stay in it during the agreed time period, prop your door open, and let the participants come visit and see it. When you participate in a Cabin Crawl, you just meet up with the group that wants to view cabins at the designated time, you are given the list of cabin numbers, and you proceed to visit the cabins that people have volunteered to open for viewing.