Vertical shooting just makes everything very different. It is just unusual for our eyes and therefore becomes more attractive at once. That's how our brain works :)
Interesting centered composition with few diagonal lines and amazing usage of additional light to get even more shadows just where they had to be to improve final composition even more.
The result is pretty abstract and just for an inexperienced viewer it may take quite a lot of time to realize what he do see on this photo. And this is very good, since some more work for the brain is always have overall positive effect!