A childlike sense of play is what is reflected in this image.
The idea that something so simple can generate an enormous amount of joy is presented by a dream with a swing set in it.
If you have personal associations with a swing set from your childhood, those should feature in your interpretation. Sometimes the most joyful images can show up with a sense of distortion in a nightmare.
A nightmare simply means the stakes are higher; such a dream may be calling for more of this playfulness in your life as something more important than you might think.
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