A fun, childhood custom that my informant always enjoyed around Christmas time is called the German Christmas Pickle.
Her grandmother is of German descent and learned the custom from her grandparents. The custom is done on Christmas Eve evening. The children will gather around the Christmas tree, which at this point is covered in decorations. Prior to the children gathering around, an adult will have hung up a pickle ornament, which they try to conceal in the tree. The children will then try to spot the pickle ornament first.
The legend is that whomever spots the pickle first will have good luck for the rest of the year.
I asked my informant, “Why a pickle?” and she said she had no idea, but that perhaps because it is green it blends in, making it hardest to spot.
In doing my own analysis, the most observant, the quickest eye, keen of senses, child most likely will be the one to spot it first, getting the good luck. So this pushes children to perhaps work on being observant and sharp of the senses. Of course it could be purely based on luck that a certain child just spots the pickle first. So it is hard to say if it truly has a purpose or not, other than to be a fun, light hearted game.