A few important things happen in this little sequence. Jones and Cage get it on (again). They ride a motorbike in his and hers helmets (safety first, nice work guys). Jessica says that all she has is her "professional reputation", over shots of her day drinking and dragging a man from his car. But none of that is as important as her straight up slamming a guy with her foot right through a floor covered in water. Who knows (or cares) why that particular room is flooded or even who that guy is. It was clearly added to the trailer for pure awe-inspiring effect and it works damn well.