It is a common thing to check your emails in the morning for example so some of those people might have been doing that.
When I have free time I like to fully concentrate in what I am doing; if I am at an airport or some new place I will fully concentrate in observing the new surroundings. When I decide to work, I will work and not do something else. When I decide to relax I truly relax and stop thinking about other stuff. It really varies with my motivation levels.
Oh and I might just walk around without a clear objective other than collecting some steps to my health app to make me feel better