Imagine were asked to create some foil balloons shaped like plus signs. They were to be silver foil that was printed white and be able to float downwards when filled with helium.
After they had been produced we were told they were being used for the new freeview plus advert with the balloons being used to look like falling snow. This can be seen here
http://www.youtube.com/watch?v=ysFMrrd-3vs