beta
I’ve seen people wondering this. It gets revealed later in the novel
[Spoilers for the novel beyond what has been translated online]
I read a machine translated version of the kr novel. Eventually, we get to read about all the events so far from the perspective of jigu. Jigu actually starts suspecting yeonwoo of being neutaa when they were voice chatting and he overheard the announcement in the apartment about his mom’s car blocking. He recognized the license number and realized they were in the same apartment. Then he concluded it was yeonwoo from process of elimination.
He sent the random message to see if he gets a notification to confirm his suspicion.
I’ve seen people think that he started suspecting after neutaa changed his appearance to look like him, but jigu didn’t even realize the similarities until neutaa said it himself lol
He logged out back then because he was startled by the announcement, not the clothes change!