Each dot follows its
own pattern. Looking at the first square, the dot in the bottom left corner alternates
between being in the bottom left corner and the bottom right corner of the
grid. In the centre square of the bottom row, the dot moves one place upwards
each step. The dot in the centre square switches from the top left and top
right corner of that centre square. The dot that begins in the top left corner
alternates between not moving and moving two places to the right. Finally, the
dot that begins in the top right corner moves one place left and one place
downwards.