PARADOX! :D
If an object resting on the floor is pushed through a portal falling flat onto it, and it (the object) can get through, the object in one of the videos on their site show a teapot sitting on the floor which is in view through the portal it just came out of. If this happened, gravity from both the floor sideways and the floor flat under the current location of the object would be acting on the object. Which direction does it fall?
tl;dr: I just blew your mind.