"mach" is imperative singular, "macht" is imperative plural. So "mach bitte das Licht aus" is addressing Honecker directly (which is most likely intended here),

"mach" is imperative singular, "macht" is imperative plural. So "mach bitte das Licht aus" is addressing Honecker directly (which is most likely intended here), where "macht bitte das Licht aus" would also address the people with him.