If her performance as “out of work mother who’s about to lose her home†in these SNL promos is any indicator, Katy Perry is going to set the stage on fire this Saturday. Yes, like a firework. Did you see the depth with which she subtly concealed her anguish in the line “Oh no, my home� How carefully her character attempts to appear cool and non-emotive? Then finally, the plaintiveness of the final admission: “I’m sad.†So understated. So carefully repressed, with so much feeling roiling deep, deep, deep under the surface. Someone call the Academy!