On the left top back corner wall the blue-grey characters, 批林批孔专栏 mean, “Billboard for Criticizing Lin Biao and Confucius.”
On the right top corner is an old style loud speaker box with a red five-star on it. This was used for making public announcements.
You can see two book bags in the painting similar to the one here.
Mao’s quotations in Russian.
Young Red Guards learning about agriculture in the fields.
The slogan on the boat is, 为人民服务 “Service to the People.” There is an ethnic Korean woman with a bundle on her head in the lower right corner in traditional Korean clothing. Songhua Lake is located in Jilin province, which neighbors North Korea.