A Tanka should include yugen "a feeling both broad and deep, a subtle and profound atmosphere, and infinite tranquil space with lingering suggestiveness."
All of that in five lines? Yes, and Grace has also asked us to write three Tanka, while including a mysterious instruction about linking up with another poet.
*
day's sky clothed in grey
and night's sky clouded in black
give way to a dawn
of glorious enchantment
intoxicating the birds
*
day's sky wrapt in blue
bright birds soaring above green
intoxicate Man
who sighs, unable to fly
*
Man, the envious,
accomplishes much on Earth:
now flies, dives and soars
while birds, who do not envy,
still sing to welcome the dawn.