The poisoned perfume bottle as Villanelle's modus operandi turned out to be very prophetic of real-life events. Russian former spy Sergei Skripal and his daughter, Yulia, were poisoned with Novichok nerve agent in Salisbury in early March, just a few weeks before the air date. The delivery device was later determined to be a fake perfume bottle.
A drawing of a woman with long, curly, dark hair was the only thing that seemed to provoke an emotional response from Villanelle during her baseline assessment. This is the same sort of hair that Eve Polastri has (although she usually ties it back). The assessment occurred before she saw a photo identifying Eve.
Following the assessment, Villanelle and Konstantin have a conversation in a large square. This is Place Vendôme and the backdrop of the scene is the Ministere de la Justice.