In a few scenes it appears that Lorraine's accent is kind of all over the place and while some assumed it was Theron not being able to really maintain it, the truth is that Lorraine is a CIA agent impersonating both an MI6 agent and a KGB agent.
Lorraine primarily uses the Soviet Makarov PM, heavily based on the iconic Walther PPK as her weapon of choice during the movie. While this can be explained by the operating environment she's in (East Berlin), it's also a symbolic reveal that she's not actually an English Super Spy like James Bond, but an agent of another country. She also arranges for her East German asset to smuggle the gun into the hotel room in Paris to allow her to assassinate the KGB agent and his security detail, in order to muddy the waters when his handlers try investigate and mask all CIA involvement when tying up that loose end.
Delphine wears a choker through much of the film. In an early scene, she tells Lorraine, "I knew you wouldn't choke!" Delphine is ultimately choked to death. (Lorraine is not).
