It would be easier -- and a way to play quickly -- to emulate e-ink in software on your Macbook. Then you can "learn about reducing graphics quality" and "see what it looks like and how it feels"
For graphics quality, you want to look at thresholding algorithms. They can be quite complex (or simple).
1. Global threshold. Pick a brightness, brighter than that is white, darker is black
2. Same as #1, but pick the threshold by looking at the average brightness of the screen
3. For each pixel do the algorithm for #2 on a NxN window around the pixel (avg neighbor brightness), then threshold based on that.
and so on.
Also look at dithering. Threshold will work great on text, lines, shapes -- but dithering is good for photos and blocks of color. The trick might be to analyze the image and come up with areas that should be dithered and others that should be thresholded.