Dictionary.net

Marketing deceptions. The term is mainstream in this generalsense. Among hackers it's strongly associated with bogusdemos and crocked benchmarks (see also MIPS,machoflops). "They claim their new box cranks 50 MIPS forunder $5000, but didn't specify the instruction mix - soundslike smoke and mirrors to me." The phrase has been said toderive from carnie slang for magic acts and "freak show"displays that depend on "trompe l"oeil' effects, but alsocalls to mind the fierce Aztec god Tezcatlipoca (lit. "SmokingMirror") for whom the hearts of huge numbers of humansacrificial victims were regularly cut out. Upon hearingabout a rigged demo or yet another round of fantasy-basedmarketing promises, hackers often feel analogouslydisheartened.