Hi,

the graphics are only renderd once at the end of draw(), so on each frame there is only one image displayed.
Therefore delay() is not an option.
frameCount is a good possibility to change things over time.
For example:

1. int distance;
   
   void setup() {
     size(200, 200);
     frameRate(25);
   }
   
   void draw() {
     background(204);
     distance = 10+frameCount0;
   
     for (int i = 0; i < 4; i++) {
       for (int j = 0; j < 4; j++) {
         rect(20+distance*j, 20+distance*i, distance/5, distance/5);
       }
     }
   }