One of the cool features of JPEG files is that there's the option to save low frequency components first. This means that a partially downloaded image will be displayed at low resolution instead of being cut off.
All characters fit within a 5 pixel square, and are safe to draw on a 6x6 grid. The design is based off of lcamtuf's 5x6 font-inline.h, which is itself inspired by the ZX Spectrum's 8x8 font.
