(2) "Geleshan Enlightenment and Zhatu Cave Zen" refers to the revolutionary way, Marxist-Leninist Zen. "Elysium" shows that people have mastered the revolutionary truth.
(3) Looking out of the window, it is already the Spring Festival. The "old scene" refers to the rule of the Kuomintang reactionaries, and the "Spring Festival" refers to the prospect of the revolution's imminent victory throughout the country. Together with the banner "All difficulties are coming", it expresses the revolutionaries' belief in the imminent victory of the revolution and their vision for the future.
④ Spring can't close the garden, and an almond goes out of the wall: Borrowing the poems of the ancients, it not only expresses contempt for the reactionaries (it's futile to stop the revolutionary victory), but also expresses hope for victory (an almond goes out of the wall). The banner of "Return in Spring" vividly summarizes the revolutionary situation at that time.
⑤ Two skylights-vent and damper-protrude. This couplet summarizes the inhuman life of revolutionaries in prison. Root forehead "enjoys it" expresses the revolutionary feelings of revolutionaries who enjoy suffering, and it is also a clever exposure of reactionaries persecuting revolutionaries.