It's rude to refuse to talk to others.
Zelda is very busy at work and has to complete a project very soon.
Zelda wants to focus on her urgent project.
Zelda stops to chat for a few minutes with her colleagues, and then goes back to her project.
Zelda sees coworkers in the cafeteria but pretends not to see them in order to save time.
Zelda's coworkers are happy to have chatted with her for a few minutes.
Zelda's colleagues feel they're being ignored.