Like stripes, bars represent bondage; see “bound”
Vision: Seeing yourself behind bars: you are either very dependent on others or are prevented from doing something. Looking at barred windows: you are isolating—show more interest in others. Maybe you are longing for a person far away. Seeing a huge iron gate: you have too many unrealistic hopes and wishes.
Depth Psychology: Bars are either a warning about unrealistic wishes or indicate your longing for a person who is far away.