My kids loved making that mask. We went to WS the last day, I played it up by asking if they wanted to do arts & crafts. They couldn't wait. At each country, you need to look for the Kidcot station. Just ask if you can't find it, all the CM's know what you're looking for. And if they see you coming with a mask, they'll usually just automatically point you in the right direction.
At the first country, they will give you a cardboard mask on a paint stick. There is a basket with markers for the kids to decorate the mask. At each country, they will stamp the handle with their country's stamp, and attach a paper representative of a toy of that country. Then there will be more markers at each stop as well, for them to continue decorating.
My kids loved this! Each time they didn't want to get up from the table, and they were in a hurry to get to the next one. My ds4 decided his was a bear monster mask, but little like him, lol. He thought it was great fun to roar and scare nonexistent dangers.
IMHO Canada had the best station. They read a story to the kids, which was written by a Canadian author. It was "I'll love you forever". I wish I'd bought the book, and probably still will. My ds is still repeating the theme of the book.