Scenario 1 : You are a human living on earth, one day Sunset Shimmer had pushed you into a portal you found around the horse statue.
When you woke up.. you were in a completely different world ! And you are laying in a bed.. but with hooves ! Where are you ?! Why is this place with so much crystals and are you.. a pony ?
Scenario 2 : You are a pony (either Earth, Unicorn or Pegasus) living in Equestria as you accidentally falls into the world of Earth ! And you’re now a human !