Extra points if they break to the point they have to turn off their video.
This is actually a very good and general principle of behaviour: "act as if anything you say to anybody is overheard by everybody else in the world". Maybe you won't ever become a sneaky manager if you follow this principle, but you will certainly sleep well at night.
I was on a cybersecurity team. We were all guys and much younger at the time, so perhaps not the most mature. We also were pretty decent at what we did, so our egos were...let's go with our egos weren't in check. As a result we had a running competition of who was the best at defending their laptop from getting hacked by one of the others, and who was the best at hacking them. Notice of success was delivered by setting the desktop background and/or screensaver to one of the Absolut ad images with Fabio style men dressed in skimpy clothing. Have I covered the not very mature at the time? This also was around 2002, so social awareness of just how bad this behavior was, and how toxic it could have been if female colleagues saw it, was not on our radar at the time.
Anyways, this all came to a halt one day. The team lead had been hacked a couple days before, and the person doing it went a little overboard and put the image [1] on the screensaver, the main desktop, and the external monitor desktop. The lead deleted the image from the screensaver and the main desktop, but didn't expect it on the external monitor desktop and didn't check.
He discovered it when he connected his external monitor port to the big screen just before a presentation to a small room full of 2-stars and SESs, who were shocked at what they saw on the big screen. Our team got an earful (rightly so), and we were probably lucky we didn't get fired. That was the last of that competition, and he was getting razzed about it a little four years later when I left the company for greener pastures.
[1] The image. Warning, it is a graphic male image. https://www.advertisingarchives.co.uk/detail/32171/1/Billboa...
I'd set my DISPLAY environment variable to his desktop, then use xv to open whatever gross / unflattering / whatever pictures I'd found on the net that day.
Thankfully it only showed my phone number and not my name, and it was ambiguous enough not to be totally obvious. But still....