You are drawing a picture with leds. All are fully OFF or ON, no brightness levels.
Something like below only a different picture, different size, this is a 12x6 box in 16x8 space:
// OOOOOOOOOOOOOOOO
// OOXXXXXXXXXXXXXXOO
// OOXOOOOOOOOOOXOO
// OOXOOOOOOOOOOXOO
// OOXOOOOOOOOOOXOO
// OOXOOOOOOOOOOXOO
// OOXXXXXXXXXXXXXXOO
// OOOOOOOOOOOOOOOO
My bits will be 0 for O and 1 for X, 2 bytes or 1 int per line.
If I want, I can store many different 'bit-pictures' in PROGMEM and try to animate even.