This small poster was published by the Hong Kong-based pro-Beijing Wen Wei Po (Wen Hui Bao, 文汇报) in 1967.

It was exhibited in the outdoor Red Guard exhibition Long Live the Great Proletarian Cultural Revolution on 25 May 1967 in Tian'anmen Square. The image was adapted from a photograph taken on the occasion of Mao receiving the Red Guards on 18 August 1966. Mao wears a Red Guards' armband.

Source:

Winnie Tsang, "Creating National Narrative -- The Red Guard Art Exhibitions and the National Exhibitions in the Chinese Cultural Revolution, 1966-1976", Contemporaneity: Historical Presence in Visual Culture 3:1 (2014) DOI 10.5195/contemp.2014.58