Taking ten minute screenshots is not a good practice. Why not just measure on output or have regular meetings?
What kind of job requires ten minute screenshots? Definitely not a software development job.
What kind of job requires ten minute screenshots? Definitely not a software development job.
But in general, the problem with surveillance is that it is just all about appearances. People usually learn to "look" busy instead of being productive and that is counter-productive to actual productivity when people are just pre-occupied with appearances.
Another problem is that it creates an atmosphere of low trust in the company. When there is an atmosphere of low trust, people will be less motivated to work hard and to give their whole effort since they will feel they are just expendable since the manager doesn't trust them.