Just take the shot, duplicate it, make it 3d, turn it upside down (rotate the z axis 180 deg), put it in a layer under the first one, then move it up in y space to match where his feet would be hitting the floor. Then bring down opacity, apply a blur as liked to the bottom layer, add a gradient mask so that the reflection fades away, possibly animate the position of the gradient as he walks forward. Is this what you mean?