In episode 17, Yukko trying to stop tsukkomi-ing Mai. At the end of this scene, there is a part where Yukko made an ayatori (a traditional Japanese game for children) like below:
And after that, Mai-chan seems to be shocked.
What pattern is this? What's the meaning of it?
Relevant video on YouTube.
This apparently the "Gunma prefecture with the shape of a soaring crane" （鶴舞う形の群馬県）. You may not know this but the shape of the prefecture somewhat resembles a crane flapping its spread wings.
The purpose is likely to add absurdity as so many people heard the tsukkomi she put all of her heart in. Take note that the school is based on the high school the original creator attended, Isesaki Commercial High School located in the Gunma prefecture. This seems to be a meta joke on how the tsukkomi was loud, everyone in the Gunma prefecture heard her.
