A shower in the balcony would �compel� people to  experience nature every day. Every morning the drizzling of water and the greenery of foliage would launch  the user in to a new horizon purifying  mind and soul towards the horizon.  Nowadays people might travel thousands of miles to  find spirituality  in a tropical paradise, but now your balcony is your tropical paradise!    
While in the winter the shower can be enclosed by glass in the  summer it can just be enclosed by an flowering curtain and climbing plants thus  experiencing  the blossoming and falling of seasons.  

The water used  during the shower would  be just collected in the drain channel in the balcony and used straight away to regularly watering the plants.  An outdoor shower in the balcony would increase the floor space available inside your apartment allowing you  to make or instance a larger living room. Up to the designer to find the best spatial solution to fit  the outdoor shower with the internal arrangement as well as to use the shower as a water feature.

In the attached images, it is just a basic example �Shower on the sky�, fundamentally my idea is to look for a alternative as well as simple spatial planning to match a more funky  and pure urban life style, where people are  led into more  spiritual  and sustainable approach.