Emulating greyscale on a 1-bit LCD
About the only way to simulate grayscale using a 1-bit display is to do pixel averaging, e.g. using a square of four pixels to represent one pixel in the original image,

0 pixels on (white) = 0%
1 pixel on (light gray) = 25%
2 pixels on (medium gray) = 50%
3 pixels on (dark gray) = 75%
4 pixels on  (black) = 100%


Unfortunately, you don't have enough pixels on your screen, and the ones that are there are too big to allow this technique.