Approximates the shape with horizontal and vertical lines only to create a blocky look.
Link the #Points and the Noise Offset parameter to a slider and keyframe them to animate the shape over time.
The Blockify expression creates results similar to the Mosaic effect of After Effects, but operates on shape paths instead of pixels. So the result is still a path and not an image.
In this example we animated some random paths on a shape layer using the trim path modifier. Then we applied the Blockify iExpression to it and keyframed the noise to change the blocks over time.
Here we applied the Blockify iExpression to our iExpressions icon shape and animated the number of points and the noise offset parameters (by linking them to sliders). By increasing the number of points over time, the shape becomes more and more accurate. Due to the noise, the blocky vary in size and due to the noise offset, they travel along the shape.