Referencing Forum post #651, magical mitten doesn't appear after hitting left most box many times. Definitely not one box in three. See below.

"Follow-up: the Magical Mitten actually comes from the gift box at the left end of Happyville, not the tripod. That gift box now springs back about 30 seconds after someone opens it, so there's always another chance at a Mitten before the Extra Frosty Snow Zone. Give it four good hits; about one box in three holds a Mitten. The rooftop tripod also answers every swing now."