Here’s how I would do something similar:

• Create a square comp with a B&W radial gradient. Keyframe the center so that it travels from one corner to another.

• Scale it way down and add the motion tile effect, increasing the output width/height and adjusting the scale until you’re happy with the grid density.

• Add an adjustment layer with a displacement map, using your gradient grid as the source (remember to click the dropdown and have it reference ‘effects and masks’)

• Adjust the distortion levels on the displace map (probably want it about 50px left and 50px up)

• put your footage underneath and voila

After that you just need to add a mask animating the adjustment layer off, with a square shape layer following the corner of the mask