Width and height both zero: the drawing code sees the zero and draws nothing.

The sprites, end to end from here to the code at START. Each is a width byte (bits 0-3 the width in bytes; bits 6 and 7 the mirrored and upside-down flags, toggled in place as objects face about), a height byte, then a mask byte and an image byte for each cell, the bottom row first. On the tape every sprite is the right way round.