if you are using the recipe that calidawn posted with this tecnique, you don't have to freeze the transfer, you can pop it in the fridge until firm.
What i do, is first outline, then using parchment w/a cut tip(because i don't want to wash everything) then fill in the picture. Then i switch to a bag with a tip 12 or 10 and fill in the back. Then gently spread that icing on the back. Pop the whole thing in the fridge and let it get hard. When you take it out remove the waxed paper from the board, and flip the picture with the waxed paper still on, on to the cake. After the picture is on the cake then remove the waxed paper. If it has started to get to warm and the picture is sticking place the cake back in the fridge until hard. Then the paper should peal right off without a problem.