Sabina’s objection to communism is an aesthetic one, not an ethical one. She hates the “mask of beauty” worn by communism, which Sabina calls “Communist kitsch.” A prime example of “Communist kitsch,” according to Sabina, is the May Day parade. Everyone dresses up in red, white, and blue, and they smile and cheer “Long live life!” which really means “Long live Communism!” but people mostly ignore this.
As communism suppresses what makes one an individual—such as opinions and personal desires and freedoms—Sabina believes that it masks beauty. The May Day parade ignores the obvious—that the people are all forced to be there—and this is why Sabina considers it kitsch. In this case, communism is the metaphorical shit.