Take a look at the examples that come with Processing, for example this one. The setup() method runs once. The draw() method runs continuously at about 60 fps. So it is already a loop (which you don't want to slow down). And it only displays the result at the end of each draw() loop. That is a frame. Your code tries to do everything in a single loop, but then you only see the end result. You need to use the draw() loop for what it is... a loop that draws (continuously). So never use delay like this. Only people who are very unfamiliar with Processing and/or arduino users do this.

Instead you could do something like this...

Code Example