The former glamour model posed naked on the Diary Room chair in the middle of Trafalgar Square, with only some strategically-placed vegetables covering her modesty, in an attempt to keep unethically-sourced meat, eggs and dairy products off plates.
Eisermann, who was the first person evicted from this year's Big Brother after spending just three days in the compound, said: "Watching people trying to cope with living in the Big Brother house is great entertainment.
"But if we could see into factory farms and abattoirs in the same way, I guarantee we'd all be choosing to evict animal products from our diets."
PETA has previously worked with Celebrity Big Brother winner Chantelle Houghton, who unveiled a vegetarian/vegan starter kit in a dress made entirely of lettuce last year, and Big Brother 2011's special guest Pamela Anderson, a devout supporter of the animal rights group.
Big Brother continues nightly on Channel 5.
Big Brother - Day 19 in pictures:
Copyright: Channel 5