Green Flag, then move the mouse to one location & WAIT. With the Forever Loop there are 2 designs, 1 the front motionless design & the constantly changing background design. Space to see Project Thumbnail
Thanks to @FelixBrighton. I made 2 remixes. This one takes the addition of a Random Operator block for the size of the pen that "draws" the lines AND the Forever Loop. Version 1 https://scratch.mit.edu/projects/822674843/