Two directions here, like a two-way mirror. First: the world is not disturbed by this devotee. No one feels threatened, anxious, or uncomfortable around them. They are not a source of fear for anyone. Second: the world does not disturb this devotee either. The ups and downs of life do not rattle them.
Elation, envy, fear, and anxiety — these four emotions toss the mind around like wind tosses a leaf. The devotee Krishna describes is free from all four. Think of an old banyan tree. Storms come and go, but the roots hold firm. And under its branches, birds and travelers find shade and shelter. That is the kind of presence this devotee carries — steady within, and a source of calm for everyone around them.