(2) "Enlightenment is in Geleshan, Zen is in Zhazidong" means the road of revolution, the Zen of Marxism-Leninism. Elysium tells people that they have mastered the revolutionary truth.
(3) Looking at the cave is still the same, and looking out the window is the Spring Festival. The "old scene" refers to the rule of the Kuomintang reactionaries, and the "New Year" refers to the prospect that the revolution will soon win in the whole 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 of the revolution.
(4) Spring can't be caged in the garden, and an almond goes out of the wall: to borrow an ancient poem, it not only expresses contempt for reactionaries (it is futile to stop the revolutionary victory), but also expresses hope for victory (an almond goes out of the wall). The banner of "Returning 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. Gene's "Enjoying in it" expresses the revolutionary feelings of revolutionaries who take pleasure in suffering, and it is also a clever exposure of reactionaries persecuting revolutionaries.