With some species, this can take months, but with many more, such as with the Monarch, the whole process will happen in just a few days time. This is when the actual transformation is occurring. Wings and other parts of the soon to be butterfly are being enlarged. A light placed behind one at this step may give you a view into the cocoon. A magnifying glass can also be carefully used to see if you can peek inside at the developing going on inside the cocoon.
Observation again needs to be picked up as hatching starts to occur.
One minute you will look and the cocoon will be whole, and seemingly minutes later, there will sit a butterfly. Their wings will appear squashed and children may assume something is wrong. The butterfly will 'pump' life into her wings. They will unfold into all their grandeur. Allow the butterfly to fully open her wings, giving several hours for this step.