I created the ripple effect by combining the caustics plugin with the radio waves plugin, producing a ripple that I could repeat that would also have a 3D feel to it.
I added an adjustment layer to my composition above the video footage but below the frame of the mirror to help maintain the illusion of the of the mirror surface rippling. To this I added the caustic effect.
In a separate composition I added the radio waves effect adjusted the setting to produce a set of rings that would radiate out from a central point.
To create multiple ripples I duplicated the radio waves and repositioned them for the composition.
I added a fast blur to distort the ring slightly.
Afterwards I brought the separate composition to the main comp, and set the caustic water surface to the import composition.
The final effect was water ripple that radiated outwards, that also distorted the image below.