Fractals are repeating patterns that in this case originate from a simple mathematical formula including imaginary numbers. Here displayed is a part of the Julia Set, which is closely related to the beautiful Mandelbrot Set.
Spirographs are the accumulation of different oscillations onto to axis respectively and the path of them being followed by line over time. Typically, they are build physically and attached to a pencil that draws on a piece of paper, but in this case, I simulated the same thing in Excel.
Here are more examples with varying frequencies and sampling rates.
Screens are built up of discrete pixels with black lines in between. Here is a picture of an originally white screen, I added some Photoshop effects on the pixels: