Physical Pixel

Hello everyone, just came to report an issue in the code of the introductory Arduino exercise "Physical Pixel". I tried it with processing 2.1.2. I added a little delay in the first case of the if in the method draw().

just came to report an issue in the code of the introductory Arduino exercise "Physical Pixel".

What is it?

I added a little delay in the first case of the if in the method draw().

Where? Why?