Why does Villlanelle rewind the recording in 1x03 (Killing Eve)?

When Eve and Bill go to Berlin to investigate one of Villanelle's murders, it shows Eve in her hotel room on video call with her husband, Niko, then Bill knocks on the door and Niko asks Eve "is that Bill?" to which Eve replies yes. The scene then cuts to Villanelle in her own hotel room, listening to what is happening in Eve's room (she's obviously bugged it) and it shows her rewind the audio to the part where Bill knocks and Niko says "is that Bill?"

Why does she rewind the audio? What was relevant about that moment?

There are no answers yet.
Be the first to answer this question.