We often interpret a lack of eye contact to mean that someone is not credible or not competent, and as a public speaker, you don’t want your audience thinking either of those things.
At the IT help desk, I used to stare at my monitor the entire time I was explaining a software fix to a colleague. Reading this section made me realize that failing to look up probably made me seem disconnected or like I was unsure of my own troubleshooting steps. Now, even if I am typing a command or waiting for a diagnostic to run, I make sure to pause and look the person in the eyes when answering their questions. Making this small adjustment has helped me build better rapport and appear much more credible in my technical support role.