1. Convert the image to a symbol.
  2. Adjust the brightness/contrast of the symbol, setting the values to two.
  3. Clone the symbol.
  4. Adjust the brightness/contrast of the cloned symbol to a much higher value.
  5. In the layers panel, select both symbol instances and choose Modify > Symbol > Tween Instances.
  6. Set the number of frames to around five.
  7. Experiment with the timing of the frames and loopinguntil you get the effect you are looking for.
  8. Download the PNG file