juice + a balloon over the bottle immediately raises the possibility that someone is experimenting with fermentation.
However, the photo alone cannot tell us exactly what was inside the bottle or what your niece intended to do with it.
It could potentially be a science experiment, a fermentation project, or simply an unusual homemade setup.
The Balloon Is the Biggest Clue
The balloon isn’t normally part of an ordinary juice container.
Its presence suggests that whoever assembled this wanted to observe or manage gas production.
In educational demonstrations, balloons are used
