In January, Cesar Garcia, LAXART’s former associate director and senior curator, opened his own Los Angeles gallery and called it the Mistake Room (www.tmr.la)—a moniker inspired by Glenn Kaino’s performance art piece by the same name. The new exhibition space, housed in a former clothing factory on the southern edge of the downtown industrial center, is one of the city’s first midsize galleries to host site-specific exhibitions. Garcia says he started the nonprofit to broaden Los Angeles’s perspective and pre…