Press 'r' for randomness.
Press 'h' to toggle interface.
Regenerate

View on a bigger screen for more control.

Scale 1

Scale each cell by a random value.

Logic: Each cell is scaled down by a random value from a set of 20% to 100% (with a 20% increments so five values in total). Depending on the Scale Side choice cells are scaled along the corresponding axis and from chosen side.