Dar el gatazo (dahr el gah-TAH-saw) literally means "to strike or hit with a cat." However, in Mexico City that's not the intended meaning. Dar el gatazo means to look or appear in such a way good enough to pass certain standard, without actually deserving it.
A prototypical example of things that are intended to dar el gatazo is knock-off merchandise (and you will find plenty in Mexico City). A knock-off version of a Louis Vuitton purse is supposed to dar el gatazo as a real one.
Dar el gatazo can also be used in reference to people. Not a long time ago many Michael Jackson fans gathered in front of Palacio de Bellas Artes in Mexico City to do the Thriller dance. There were several Michael Jackson impersonators that indeed daban el gatazo.