Blending
Open flower.fla
Create a new layer name it reflection. Copy the flower and paste it in place on this new layer. Then select modify flip verticalto rotate the flower and then move it so that the stem is aligned with the bollom and scale it using the free transform tool as below.
Next select the reflection movieclip and then in the properties panel select the display tab and overlay. The image should look like below:
Then see if you can animate the flower to move it to the left as below (you will have to scale the bg layer making it larger or the blending option will be lost):