Jonathan, a frequent star of the family's show Keeping Up With the Kardashians, was seen arriving at Kim's Manhattan sanctuary on Tuesday (04Oct16), toting a gift basket for his best friend.
As he headed inside the building, Jonathan was asked about Kim's wellbeing, and he answered: "She's not doing so good."
He declined to go into further details about Kim's state of mind following the traumatizing incident.
Kim is being supported by friends and family, including husband Kanye West, after the robbery, and has been noticeably quiet on social media since the incident.
Sources close to the star reveal that she believes she made herself a target for the robbery by flaunting her jewels on her social media accounts.
"Kim’s in shock and blaming herself," an insider told People.com. "She’s tearing herself up that she Snapchatted the ring so much and wore it all the time. This incident is making her question everything. How she dresses, what she does."
Police in Paris are working hard to investigate the robbery and track down those responsible. While initial claims suggested the one security camera covering the Hotel de Pourtales, where Kim was staying, had been facing the wrong way, it has now been reported that detectives caught a lucky break thanks to another camera, which was covering a nail salon just down the street.
According to Britain's The Sun newspaper, the "million to one" scenario showed the men in the reflection of a mirror as they were seen strolling through a shopping mall adjacent to Kim's temporary home on Rue Tronchet.
The publication claims the footage showed the men going through an unlocked office door, before making their way into a car park where they jumped onto motorbikes and made their getaway.