At the end of a game, I normally thank my opponent, but then I don’t know whether to hang around waiting for a reply. Is there any indication that my opponent has left the game?
Click here to find out.

Note that if you leave and they come back and reply, you get a notification.
“You got chat on a finished game: link” something like that.
I believe this feature is somewhat misleading. For example, I am technically “viewing” the game, but I am in “Analyze Mode” which masks the chat almost completely, so I can’t notice when someone has wrote something, or it could be that I just have finished the game and left the window open, or I could be on the phone which doesn’t make the chat visible at all and it is kind of a nuance to scroll down and up frequently.
Yes of course, the indicator only tells if you are connected on the page, not if you are watching it. We would need something more informative like this:

Well, unless we hack your camera, we can’t really prove that you are really there eh ![]()
What it says is that “you joined the chat and didn’t exit it yet”.
There are other potential reasons it might not be telling the truth - we can’t be sure that other “clients” (3rd party phone apps) support this, and the green “presence” indicator at in the Player Card, properly.
On the other hand, if it was showing that they were here, and now it shows they are not, then they really have likely departed.
We can’t prove they are really there, but we can say that we are sure they left ![]()
Even those things are hopelessly inaccurate.
Depending on the app, you can start typing, then walk away, and it still says “typing” because you didn’t finish (which can be one reason why it seems like people type sooo slooowly!)