There's a principle of limiting collection, again linked to necessity and proportionality. If you're the employer and you're going to be looking at the data of the employee, it's all part of the transparency. Make sure the employee is aware that this is their work device. If they're using it for personal things, is there a mix? What are the expectations in terms of what the employer will have access to? Why does the employer need to have access to those things?
It's all about making sure the employer or any other organization doesn't get to collect and use more information than they need. That means looking at the purpose and looking at the context. I gave the example of truck drivers being filmed on their personal time. That wasn't necessary for safety on the roads.
Similar types of questions would be asked. The more you're going to go and get my personal information, the more you should have to justify why that is. Again, that's what privacy impact assessments do, and that's what necessity and proportionality would do. We live in a time where that technology, as you described, is more and more invasive. Sometimes there's a mix between the personal life and the work life, so that raises privacy implications.