I would like to think that she meant well. From an IT perspective, I could see not wanting all of that liquid around a laptop. I was going to try to use my laptop while pumping, but decided I could focus better if I didn't.
Oh, and if it was about not wanting to mix break with work time and thus get more time, tell them to stop having people eat at their desks then. :P
Depending on what YOU want to do, and what works best for YOU, working while pumping may be very convenient. It was for me! I bought a pumping band, so I was able to pump hands-free. It was great. I would get it all set up and then... work! This may not work for everyone, but reduced stress for me because I didn't have to worry about my work productivity while pumping.
But if thinking about your baby or reading a book helps your let-down and milk supply, then you should do what is best for you and the baby.