The crew built a pressurized bra to plump her chest on cue. It looked so fake that Robert Zemeckis threw it out and had someone do the job by hand. The gag sells the potion in Death Becomes Her: Meryl Streep’s Madeline drinks the Elixir of Life, and her body snaps back to youth, breasts and all, in one exaggerated mirror shot. To get it, the crew first designed a pneumatic bra meant to fake the rapid lift. On camera it didn’t move fast enough an…