Background: While listening to a training session via the bigbluebutton conference web-tool I was googling something and browsing on a webpage. Actually I was using chrome for listening to the conference and browsing in firefox (not a private tab). I am not 100% sure, but I was surprised when I suddenly noticed that the person giving the training was adapting/anticipating to what I was browsing. It could be random, but I am pretty sure it was not. It was quite specfic and the trainer was shortly commenting on it.
Therefore my question is if it is possible that during a web-conference the trainer can see what the participants are browsing? For example via cookies?
Furthermore my subquestion would be, if that is also possible if it is on another software/app, so like using chrome for the conference and accepting the cookies there and browsing in firefox?
I am not interested in the data privacy side of this. Just the technical aspect if it would be possible and how likely it is. I am not talking about NSA/CIA possibilities, but an IT consultant giving the training, so with somehow a technical knowledge.
EDIT: I was not sharing my screen or anything like this.
EDIT2: I was also not looking aside and then the trainer noticed it and maybe he guessed it. And it was not connected to what the person was talking about.