This code will turn all of the micro:bit's LEDs off:
display.show(Image('00000:' '00000:' '00000:' '00000:' '00000'))
This will turn them all on, to full brightness:
display.show(Image('99999:' '99999:' '99999:' '99999:' '99999'))
What do you think this one will do?:
display.show(Image('99999:' '77777:' '55555:' '33333:' '11111'))
Test them out in your code!
You can design your images on paper using a 5x5 grid.