context: Director René Vidal [Jean-Pierre Leaud] has been charged with the remake of Louis
  Feuillade's 1915 silent French movie Les Vampires. The star of Les
  Vampires, Irma Vep, was played by a French actress named Musidora. In a
  search for an actress to play Irma, René has become impressed with Chinese
  martial artist, Maggie Cheung [herself], because of her beauty, her grace, and her
  presence, he says. Maggie is hired and flies to Paris from Hong Kong.
  Unfortunately, she is three days late in arriving, which is causing havoc
  with the filming. It also doesn't help that Maggie does not speak French.First thing on the agenda is for Maggie to be fitted in her costume,
  a skin-tight latex catsuit, much like the one worn by Halle Berry in
  Catwoman. Next, Maggie grabs some lunch with costumer Zoé [Nathalie Richard] and learns
  that René Vidal's reputation as a director is going downhill. To Maggie,
  however, he seems to believe in the remaking of Les Vampires, so she
  isn't worried. Then comes the shoots. They shoot the scene where Irma is
  chloroformed and a double substituted in her place. At the viewing of the
  shoot, however, René is so P.O.ed that he stomps out of the theater.That night, following the viewing, everyone drives off and leaves
  Maggie behind until Zoé happens by and offers Maggie a ride on her
  motorbike. They go to a friend's house for dinner, where everyone is
  dissing René in French and Maggie has no idea what they are saying.
  Meanwhile, out in the kitchen, Zoé and a friend are discussing Zoé's
  attraction to Maggie, and the firend advises Zoé to go for it. When she
  gets Maggie alone, the friend tells her that Zoé wants to have sex with her.
  Maggie is very embarrassed.When Maggie gets back to the hotel, she finds a half dozen messages
  from René, who's been calling every few minutes, asking her to call back.
  He asks her to meet him at his house. By the time Maggie arrives, the
  police are buzzing in and out. René has had a huge fight with his wife,
  and the doctor on call has given him tranquilizers. As René is in the
  middle of explaining to Maggie her role in the movie, he passes out.Maggie goes back to her hotel room. Almost as though she is possessed
  by the spirit of Irma Vep, she puts on her catsuit and sneaks into the
  room of a hotel guest where she finds a pile of jewelry and takes it with
  her. Like Irma Vep, she flees to the rooftop where she drops the jewelry
  over the ledge. The next morning, Maggie is so tired that she sleeps
  through her wakeup until Zoé shows up with the hotel passkey to see if
  Maggie is okay. When Maggie gets to the studio, she rehearses the scene
  where Irma kills the Great Vampire.Meanwhile, René has come up missing, and the entire crew is in
  distress. It turns out that René has had a nervous breakdown and has been
  admitted to a rest home. René's director friend, José Mirano, is going to
  take his place. What Mirano cannot comprehend is why René chose a Chinese
  actress to play Irma Vep, the epitome of the Paris Underground. Mirano
  agrees to take over direction but only if he can replace Maggie.Maggie is given a ticket to New York where she is to meet with Ridley
  Scott and then fly on to Los Angeles. Mirano views the film as it's been
  edited by René. The film is a total mess (although some reviewers claim
  that it's a "love sonnet" from René to Maggie). [Original Synopsis by bj_kuehl]
question: What is Irma Vep profession in the movie?
answer: Cat burglar